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NOTICE OF INCORPORATION 

United States Legal Document 

J^" All citizens and residents are hereby advised that 
this is a legally binding document duly incorporated by 
reference and that failure to comply with such 
requirements as hereby detailed within may subject you 
to criminal or civil penalties under the law. Ignorance of 
the law shall not excuse noncompliance and it is the 
responsibility of the citizens to inform themselves as to 
the laws that are enacted in the United States of America 
and in the states and cities contained therein. "^& 

* * 

NBIC 2007, National Board Inspection Code, 

Part 2, Inspection, Initial Code Release, 

as mandated by the requirements of the States 

of Alabama, Alaska, Arizona, Colorado, Iowa, 

Kansas, Michigan, Missouri, Nebraska, New Jersey, 

North Dakota, Ohio, Oregon, and Utah. 





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NATIONAL BOARD INSPECTION CODE 



NOTE: Pages ii through xvi are not part of this 
American National Standard 



Library of Congress Catalog Card No. 52-44738 

Printed in the United States of America 

All Rights Reserved 

©2007 
The National Board of Boiler and Pressure Vessel Inspectors 

Headquarters 

1 055 Crupper Avenue 

Columbus, Ohio 43229-1183 

614.888.8320 

614.847.1828 Fax 

Testing Laboratory 

7437 Pingue Drive 

Worthington, Ohio 43085-1 71 5 

614.888.8320 

614.848.3474 Fax 

Training & Conference Center 

1055 Crupper Avenue 

Columbus, Ohio 43229-1 1 83 

614.888.8320 

614.847.5542 Fax 



NATIONAL BOARD INSPECTION CODE 

The National Board of Boiler and Pressure Vessel Inspectors 
Board of Trustees 

D.A. Douin 
Chairman 

R.J. Aben Jr. 
First Vice Chairman 

M. Mooney 
Second Vice Chairman 

D.E. Tanner 
Secretary/Treasurer 

J. T. Amato 
Member at Large 

D.J. Jenkins 

Member at Large 

D.C. Price 

Member at Large 

M.R.Toth 
Member at Large 



Advisory Committee 

G. W. Galanes 
representing welding industries 

E.J. Hoveke 
representing National Board certificate holders 

L.J. McManamon Jr. 
representing organized labor 

G. McRae 
representing pressure vessel manufacturers 

B.R. Morelock 
representing boiler and pressure vessel users 

C.E. Perry 
representing boiler manufacturers 

C.G. Schaber 
representing authorized inspection agencies (insurance companies) 



NATIONAL BOARD INSPECTION CODE 



National Board Members 

Alabama Ralph P. Pate 

Alaska Mark R. Peterson 

Arizona 

Arkansas Gary R. Myrick 

California Donald C. Cook 

Colorado Randall D. Austin 

Connecticut Allan E. Piatt 

Delaware J ames B - Harlan 

Florida Mario D. Ramirez 

Georgia Earl Everett 

Hawaii Keith A. Rudolph 

Idaho Michael Poulin 

H|j n0 j s David A. Douin 

Indiana Daniel Willis 

l owa Michael Klosterman 

Kansas Donald J. Jenkins 

Kentucky Rodney Handy 

Louisiana William Owens 

Maine Jo nn H - Burpee 

Maryland Karl J. Kraft 

Massachusetts Mark Mooney 

Michigan Robert J. Aben Jr. 

Minnesota Joel X Amato 

Mississippi Kenneth L. Watson 

Missouri GaryScribner 

Montana James McGimpsey 

Nebraska Christopher B. Cantrell 

N evac |a Gerard F. Mankel 

New Hampshire Wayne Brigham 

New Jersey Milton Washington 

New York Peter L. Vescio 

North Carolina Jack M. Given Jr. 

North Dakota Robert Reetz 

Ohio DeanT.Jagger 

Oklahoma Tom Monroe 

Oregon Michael D. Graham 

Pennsylvania Jack A. Davenport 

Rhode Island Benjamin Anthony 

South Dakota Howard D. Pfaff 

Tennessee Martin R.Tbth 

Texas Anthony P. Jones 

Utah Rick Sturm 

Vermont Wesley E. Criderjr. 

Virginia Fred p - Barton 

Washington Linda Williamson 

West Virginia Arthur E. Adkins 

Wisconsin Michael J. Verhagen 

Chicago, IL Michael J. Ryan 

Detroit Ml Michael Barber 

Los Angeles, CA JovieAclaro 

Milwaukee, Wl Randal S. Pucek 

New York, NY William McGivney 

Alberta Ken K.T. Lau 

British Columbia Malcolm Bishop 

Manitoba Terry W. Rieger 

New Brunswick Dale E. Ross 

Newfoundland & Labrador E. Dennis Eastman 

Northwest Territories Steve Donovan 

Nova Scotia Peter Dodge 

Nunavut Territory E.William Bachellier 

Ontario Frantisek Musuta 

Prince Edward Island Kenneth Hynes 

Quebec Madiha M. Kotb 

Saskatchewan Brian Krasiun 

Yukon Territory Daniel C. Price 



NATIONAL BOARD INSPECTION CODE 



National Board Inspection Code Committees 



Main Committee 



T. Parks, Chair 

The National Board of Boiler and 

Pressure Vessel Inspectors 

R. Wielgoszinski, Vice Chair 
Hartford Steam Boiler Inspection and 
Insurance Company of Connecticut 

R. Heiiman, Secretary 

The National Board of Boiler and 

Pressure Vessel Inspectors 

R. Aben 

State of Michigan 

S. Bacon 
Conoco Phillips 

D. Canonico 
Canonico & Associates 

D. Cook 

State of California 

P. Edwards 

Stone & Webster, Inc. 

G. Calanes 

Midwest Generation EME, LLC 

J. Given 

State of North Carolina 

F. Hart 

Furmanite Corporation 

C. Hopkins 
Seattle Boiler Works 

J. Pillow 

Common Arc Corporation 



M.R. Peterson 
State of Alaska 

A. Piatt 

State of Connecticut 



R. Reetz 

State of North Dakota 

H. Richards 
Southern Company 

J. Richardson 
Consultant-Dresser Inc. 

J. Sekely 

Wayne Crouse Inc. 

R. Snyder 
ARISE, Inc. 

H. Staehr 
EM Global 

S. Staniszewski Jr. 

US Department of Transportation 

R. Sulzer 

The Babcock & Wilcox Company 

H. Titer 

MIRANT Mid-Atlantic 



J. Yagen 
Dynegy, Inc. 



NATIONAL BOARD INSPECTION CODE 



Subcommittee for Installation (Part 1) 



H. Richards, Chair 
Southern Company 

P. Bourgeois 
St. Paul Travelers 

S. Cammeresi 
Consultant 

R. Donalson 

Tyco Valves and Controls 

G. Halley 

ABMA 

C. Hopkins 
Seattle Boiler Works 

B. Moore 

Hartford Steam Boiler Inspection 



M.R. Peterson 
State of Alaska 

A. Piatt 

State of Connecticut 

R. Snyder 
ARISE, Inc. 

R. Sulzer 

The Babcock and Wilcox Company 

H. Titer 

MIRANT Mid-Atlantic 

J . Yagen 
Dynegy, Inc. 



Subgroup for Installation (Part 1) 



Boilers 



C. Hopkins, Chair 
Seattle Boiler Works 

P. Bourgeois 
St. Paul Travelers 

C. Halley 
ABMA 

B. Moore 

Hartford Steam Boiler Inspection 

A. Piatt 

State of Connecticut 

R. Sulzer 

The Babcock and Wilcox Company 



Pressure Vessels and Piping 

J. Yagen, Chair 
Dynegy, Inc. 

M.R. Peterson 
State of Alaska 

H. Richards 
Southern Company 

R. Snyder 
ARISE, Inc. 

H. Titer 

MIRANT Mid-Atlantic 



Subcommittee for Inspection (Par t 2) 

D. Cook, Chair 
State of California 

S. Bacon 

Conoco Phillips-Ferndale Refinery 

B. Barbato 

St. Paul Travelers 

D. Canonico 
Canonico & Associates 

J. Getter 
Worthington Cylinders 

P. Martin 

The United Association of journeymen and Apprentices 

of the Plumbing and Pipe fitting Industry of the United States and Canada 

G. McRae 

Trinity Industries, Inc. 

V. Newton 
Chubb & Son 

D. Parrish 
EM Global 



R. Reetz 

State of North Dakota 

J. Richardson 
Consultant-Dresser, Inc. 

J. Riley 

Chevron Energy and Technology 

M. Schwartzwalder 
AEP 

R. Shapiro 
Pac/'f7Corp 

H. Staehr 
EM Global 

S. Staniszewski 

US Department of Transportation 

R. Wacker 
Dupont 



NATIONAL BOARD INSPECTION CODE 



Subgroup for Inspection (Part 2) 



General Requirements 


Specific Requirements 


D. Canonico 

Canonico & Associates 


H. Staehr, Chair 
FM Global 


J. Getter 
Worthington Cylinders 


S. Bacon 

Conoco Phillips-Ferndale Refinery 


P. Martin 

The United Association of Journeymen and Apprentices 

of the Plumbing and Ripe Fitting Industry of the United States and Canada 


B. Barbato 

St. Paul Travelers 


D. Parrish 
FM Global 


D. Cook 

State of California 


J. Richardson 
Consultant-Dresser, Inc. 


G. McRae 

Trinity Industries, Inc. 


R. Shapiro 
PacifiCorp 


M. Schwartzwalder 
AEP 




S. Staniszewski 

US Department, of Transportation 




R. Wacker 
Dupont 



Subcommittee for Repairs and Alterations (Part 3) 



G. Galanes, Chair 

Midwest Generation EME, LLC 


B. Juarez 

OneBeacon America Insurance Company 


J. Pillow -Vice Chair 
Common Arc Corporation 




J. Larson 

OneBeacon America Insurance Company 


R. Aben 

State of Michigan 




F. Pavlovicz 

The Babcock and Wilcox Company 


M. Brodeur 
International Valve & Instr. 


Corp. 


D. Peetz 
ARISE, Inc. 


D. DeMichael 
DuPont 




B. Schulte 
NRG Texas, LP 


P. Edwards 

Stone & Webster, Inc. 




J. Sekely 

Wayne Crouse Inc. 


J. Given 

State of North Carolina 




M. Toth 

5fafe of Tennessee 


F. Hart 

Furmanite America, Inc. 




M. Webb 
Xcel Energy 



NATIONAL BOARD INSPECTION CODE 



Subgroup for Repairs and Alterations (Part 3) 



General Requirements 




Specific Requirements 


P. Edwards, Chair 
Stone & Webster, Inc. 




J. Sekely, Chair 
Wayne Crouse Inc. 


B. Schulte, Vice Chair 
NRC Texas, LP 




G. Galanes 

Midwest Generation EME, LLC 


R. Aben 

Slate of Michigan 




J. Given 

State of North Carolina 


B. Juarez 

OneBeacon America Insurance 


Company 


F. Pavlovicz 

The Babcock and Wilcox Company 


J. Larson 

OneBeacon America Insurance 


Company 


D. Peetz 
ARISE, Inc. 


M. Webb 
Xcel Energy 




J. Pillow 

Common Arc Corporation 



Speciai Subgroups for Installation, Inspection, and Repairs and Alterations (Parts 1, 2, and 3) 



Pressure Relief Devices 


Locomotive Boilers 


F. Hart, Chair 
Furmanite America Inc. 


B. Withuhn, Chair 
Smithsonian Institution 


A. Cox, Vice Chair 
Industrial Value 


S. Butler 

Midwest Locomotive & Machine Works 


M. Brodeur 

International Valve & Instr. Corp. 


D. Conrad 

Valley Railroad Co. 


S. Cammeresi 
CCR 


R. Frazen 

Great Smoky Mountain Railroad 


D. DeMichael 
DuPont 


S. Jackson 
D&SNC 


R. Donalson 

Tyco Valves and Controls 


S. Lee 

Union Pacific Railroad 


K. Fitzimmons 
Carter Chambers, LLC 


D. McCormack 
Consultant 


T. Patel 

Farvis Engineering 


L. Moedinger 
Strasburg Railroad 




G. Scerbo 

Federal Railroad Administration 




R. Schueler 

The National Board of Boiler andPressure Vessel Inspectors 




R. Stone 

ABB/Combustion Engineering 




R.Yuill 
Consultant 



VII 



NATIONAL BOARD INSPECTION CODE 



Special Su bgroups for Installation, Inspection, and Repairs and Alterations (Parts 1, 2, and 3) 



Graphite 

E. Sal tow, Chair 

SCL Carbon Croup/SCL Technic 

W. Banker 
Graphite Repairs, Inc 

F. Brown 

The National Board of Boiler and 
Pressure Vessel Inspectors 

K. Cummins 
Louisville Graphite 

S. Malone 
Carbone of America 

M. Minick 
FM Global 

A. Stupica 

SGL Carbon Group/SGL Technic 



Fiber-Reinforced Pressure Vessels 

B. Shelley, Chair 
DuPont 

F. Brown 

The National Board of Boiler and 

Pressure Vessel Inspectors 

J. Bustillos 

Bustillos and Consultants 



T. Cowley 
DuPont 

R. Crawford 
L & M Fiberglass 

D. Eisberg 

Bekaert Progressive Composites 

T. Fowler 
Retired/Spicewood, TX 

D. Hodgkinson 

Consultant 

D. Keeler 

The Dow Chemical Company 

R. Lewandowski 

Corrosion Resistant Composites 

H. Marsh 
Consultant 

D. Pinell 
ABSIS 

J. Richter 
Tankinetics, Inc. 



IX 



NATIONAL BOARD INSPECTION CODE 



National Board Inspection Code 
2007 Edition including 2007 Addendum 

Date of Issue — December 31, 2007 

This code was developed under procedures accredited as meeting the criteria for American 
National Standards. The Consensus Committee that approved the code was balanced to assure 
that individuals from competent and concerned interests had an opportunity to participate. The 
proposed code was made available for public review and comment, which provided an 
opportunity for additional public input from industry, academia, regulatory and jurisdictional 
agencies, and the public-at-large. 

The National Board does not "approve," "rate," or "endorse" any item, construction, 
proprietary device, or activity. 

The National Board does not take any position with respect to the validity of any patent rights 
asserted in connection with any items mentioned in this document, and does not undertake 
to insure anyone utilizing a standard against liability for infringement of any applicable Letters 
Patent, nor assume any such liability. Users of a code are expressly advised that determination 
of the validity of any such patent rights, and the risk of infringement of such rights, is entirely 
their own responsibility. 

Participation by federal agency representative(s) or person(s) affiliated with industry is not to be 
interpreted as government or industry endorsement of this code. 

The National Board accepts responsibility for only those interpretations issued in accordance 
with governing National Board procedures and policies which preclude the issuance of 
interpretations by individual committee members. 

The footnotes in this document are part of this American National Standard. 



® 







The above National Board symbols are registered with the US Patent Office. 

"National Board" is the abbreviation for The National Board of Boiler and Pressure Vessel 

Inspectors. 

No part of this document may be reproduced in any form, in an electronic retrieval system or 
otherwise, without the prior written permission of the publisher. 



NATIONAL BOARD INSPECTION CODE 



Foreword 

The National Board of Boiler and Pressure Vessel Inspectors is an organization comprised of 
Chief Inspectors for the states, cities, and territories of the United States and provinces and 
territories of Canada. It is organized for the purpose of promoting greater safety to life and 
property by securing concerted action and maintaining uniformity in post-construction 
activities of pressure-retaining items, thereby assuring acceptance and interchangeability 
among jurisdictional authorities responsible for the administration and enforcement of various 
codes and standards. 

In keeping with the principles of promoting safety and maintaining uniformity, the National 
Board originally published The NBIC in 1 946, establishing rules for inspection and repairs to 
boilers and pressure vessels. The National Board Inspection Code (NBIC) Committee is charged 
with the responsibility for maintaining and revising the NBIC. In the interest of public safety, 
the NBIC Committee decided, in 1 995, to revise the scope of the NBIC to include rules for 
installation, inspection, and repair or alteration to boilers, pressure vessels, piping, and 
nonmetallic materials. 

In 2007, the NBIC was restructured into three Parts specifically identifying important post- 
construction activities involving safety of pressure-retaining items. This restructuring provides for 
future expansion, transparency, and uniformity, ultimately improving public safety. 

The NBIC Committee's function is to establish rules of safety governing post-construction activities 
for the installation, inspection and repair and alteration of pressure-retaining items, and to interpret 
these rules when questions arise regarding their intent. In formulating the rules, the NBIC 
Committee considers the needs and concerns of individuals and organizations involved in the 
safety of pressure-retaining items. The objective of the rules is to afford reasonably certain 
protection of life and property, so as to give a reasonably long, safe period of usefulness. 
Advancements in design and material and the evidence of experience are recognized. 

The rules established by the NBIC Committee are not to be interpreted as approving, 
recommending, or endorsing any proprietary or specific design, or as limiting in any way an 
organization's freedom to choose any method that conforms to the NBIC rules. 

The NBIC Committee meets regularly to consider revisions of existing rules, formulation of new 
rules, and respond to requests for interpretations. Requests for interpretation must be addressed 
to the NBIC Secretary in writing and must give full particulars in order to receive Committee 
consideration and a written reply. Proposed revisions to the Code resulting from inquiries will 
be presented to the NBIC Committee for appropriate action. 

Proposed revisions to the Code approved by the NBIC Committee are submitted to the 
American National Standards Institute and published on the National Board Web site to 
invite comments from all interested persons. After the allotted time for public review and final 
approval, revisions are published annually in Addenda to the NBIC. 

Organizations or users of pressure-retaining items are cautioned against making use of 
revisions that are less restrictive than former requirements without having assurance that they 
have been accepted by the Jurisdiction where the pressure-retaining item is installed. 



XI 



NATIONAL BDARD INSPECTION CODE 



The general philosophy underlying the NBIC is to parallel those provisions of the original code 
of construction, as they can be applied to post-construction activities. 

The NBIC does not contain rules to cover all details of post-construction activities. Where 
complete details are not given, it is intended that individuals or organizations, subject to the 
acceptance of the Inspector and Jurisdiction when applicable, provide details for post- 
construction activities that will be as safe as otherwise provided by the rules in the original 
Code of Construction. 

Activities not conforming to the rules of the original code of construction or the NBIC must 
receive specific approval of the Jurisdiction, who may establish requirements for design, 
construction, inspection, testing, and documentation. 

There are instances where the NBIC serves to warn against pitfalls; but the Code is not a hand- 
book, and cannot substitute for education, experience, and sound engineering judgment. 

It is intended that this Edition of the NBIC and any subsequent Addenda not be retroactive. 
Unless the Jurisdiction imposes the use of an earlier edition, the latest effective edition and 
addenda is the governing document. 



XII 



NATIONAL BOARD INSPECTION CODE 



Introduction 

It is the purpose of the National Board Inspection Code (NBIC) to maintain the integrity of 
pressure-retaining items by providing rules for installation, and after the items have been 
placed into service, by providing rules for inspection and repair and alteration, thereby 
ensuring that these items may continue to be safely used. 

The NBIC is intended to provide rules, information and guidance to manufacturers, 
Jurisdictions, inspectors, owner-users, installers, contractors, and other individuals and 
organizations performing or involved in post-construction activities, thereby encouraging the 
uniform administration of rules pertaining to pressure-retaining items. 

Scope 

The NBIC recognizes three important areas of post-construction activities where information, 
understanding, and following specific requirements will promote public and personal safety. 
These areas include: 

• Installation 
9 Inspection 

• Repairs and Alterations 

The NBIC provides rules, information, and guidance for post-construction activities, but does 
not provide details for all conditions involving pressure-retaining items. Where complete de- 
tails are not provided in this Code, the Code user is advised to seek guidance from the Jurisdic- 
tion and from other technical sources. 

The words should, shall, and may are used throughout the NBIC and have the following intent: 

• Shall - action that is mandatory and required. 

• Should - indicates a preferred but not mandatory means to accomplish the requirement 
unless specified by others such as the Jurisdiction. 

• May - permissive, not required or a means to accomplish the specified task. 

Organization 

The NBIC is organized into three Parts to coincide with specific post-construction activities 
involving pressure-retaining items. Each Part provides general and specific rules, information, 
and guidance within each applicable post-construction activity. Other NBIC Parts or other 
published standards may contain additional information or requirements needed to meet the 
rules of the NBIC. Specific references are provided in each Part to direct the user where to find 
this additional information. NBIC Parts are identified as: 

• Part 1, Installation -This Part provides requirements and guidance to assure all types of 
pressure-retaining items are installed and function properly. Installation includes 
meeting specific safety criteria for construction, materials, design, supports, safety 
devices, operation, testing, and maintenance. 

• Part 2, Inspection -This Part provides information and guidance needed to perform and 
document inspections for all types of pressure-retaining items. This Part includes 
information on personnel safety, non-destructive examination, tests, failure 
mechanisms, types of pressure equipment, fitness for service, risk-based assessments, 
and performance based standards. 



XIII 



NATIONAL BOARD INSPECTION CODE 



• Part 3, Repairs and Alterations -This Part provides information and guidance to 
perform, verify, and document acceptable repairs or alterations to pressure-retaining 
items regardless of code of construction. Alternative methods for examination, testing, 
heat treatment, etc. are provided when the original code of construction requirements 
cannot be met. Specific acceptable and proven repair methods are also provided. 

Each NBIC Part is divided into major Sections as outlined in the Table of Contents. 

Tables, charts, and figures provide relevant illustrations or supporting information for text 
passages, and are designated with numbers corresponding to the paragraph they illustrate or 
support within each Section. Multiple tables, charts, or figures referenced by the same 
paragraph will have additional letters reflecting the order of reference. Tables, charts, and 
figures are located in or after each major Section within each NBIC Part. 



Text Identification and Numbering 

Each page in the text will be designated in the top header with the publication's name, part 
number, and part title. The numbering sequence for each section begins with the section 
number followed by a dot to further designate major sections (e.g., 1.1, 1 .2, 1 .3). Major 
sections are further subdivided using dots to designate subsections within that major section 
(e.g. 1.1.1, 1 .2.1 . 1 .3.1 ). Subsections can further be divided as necessary. 

Paragraphs under sections or subsections shall be designated with small letters in parenthesis 
(e.g., (a), (b), (c)) and further subdivided using numbers in parenthesis (e.g., (1), (2), (3)). 
Subdivisions of paragraphs beyond this point will be designated using a hierarchical sequence 
of letters and numbers followed by a dot. 

Example: 2.1 Major Section 

2.1.1 Section 

2.1.2 Section 

2.1.2. Subsection 

a) paragraph 

b) paragraph 

1) subparagraph 

2) subparagraph 

a. subdivisions 

1 . subdivisions 

2. subdivisions 

b. subdivisions 

1. subdivisions 

2. subdivisions 

Tables and figures will be designated with the referencing section or subsection identification. 
When more than one table or figure is referenced in the same section or subsection, letters or 
numbers in sequential order will be used following each section or subsection identification. 



Supplements 

Supplements are contained in each Part of the NBIC to designate information only pertaining to 

a specific type of pressure-retaining item (e.g., Locomotive Boilers, Historical Boilers, Graphite 



XIV 



NATIONAL BOARD INSPECTION CODE 



Pressure Vessels.) Supplements follow the same numbering system used for the main text only 
preceded by the Letter "S." Each page of the supplement will identify the supplement number 
and name in the top heading. 



Addenda 

Addenda, which include revisions and additions to this Code, are published annually. Addenda 
are permissive on the date issued and become mandatory six months after the date of issue. 
The addenda will be sent automatically to purchasers of the Code up to the publication of the 
next edition. Every three years the NBIC is published as a new edition that includes that year's 
addenda. 



Interpretations 

On request, the NBIC Committee will render an interpretation of any requirement of this Code. 
Interpretations are provided for each Part and are specific to the Code edition and addenda 
referenced in the interpretation. Interpretations provide information only and are not part of 
this Code. 



Jurisdictional Precedence 

Reference is made throughout this Code to the requirements of the "Jurisdiction." Where any 
provision herein presents a direct or implied conflict with any jurisdictional regulation, the 
jurisdictional regulation shall govern. 

Units of Measurement 

Both US Customary units and metric units are used in the NBIC. The value stated in US Customary 
units or metric units are to be regarded separately as the standard. Within the text, the metric 
units are shown in parentheses. 

US Customary units or metric units may be used with this edition of the NBIC, but one system 
of units shall be used consistently throughout a repair or alteration of pressure-retaining items. 
It is the responsibility of National Board accredited repair organizations to ensure the 
appropriate units are used consistently throughout all phases of work. This includes materials, 
design, procedures, testing, documentation, and stamping. The NBIC policy for metrication is 
outlined in each part of the NBIC. 



Accreditation Programs 

The National Board administers and accredits three specific repair programs 1 as shown below: 

"R" Repairs and Alterations to Pressure-Retaining Items 

"VR" Repairs to Pressure Relief Valves 

"NR" Repair and Replacement Activities for Nuclear Items 

Part 3, Repairs and Alterations, of the NBIC describes the administrative requirements for the 
accreditation of these repair organizations. 



1 Caution, some jurisdictions may independently administer a program of authorization for organizations to perform repairs and 
alterations within that jurisdiction. 



NATIONAL BOARD INSPECTION CODE 

The National Board also administers and accredits four specific inspection agency programs as 
shown below: 

New Construction 

Criteria for Acceptance of Authorized Inspection Agencies for New Construction 

(NB-360) 
Inservice 

Qualifications and Duties for Authorized Inspection Agencies (AlAs) Performing Inservice 

Inspection Activities and Qualifications for Inspectors of Boilers and Pressure Vessels 

(NB-369) 
Owner-User 

Accreditation of Owner-User Inspection Organizations (OUIO) (NB-371 ) Owners or users 

may be accredited for both a repair and inspection program provided the requirements 

for each accreditation program are met. 
Federal Government 

Qualifications and Duties for Federal Inspection Agencies Performing Inservice Inspection 

Activities (FIAs) (NB-390) 



These programs can be viewed on the National Board Web site. For questions or further infor- 
mation regarding these programs contact: 

The National Board of Boiler and Pressure Vessel Inspectors 

1055 Crupper Avenue 

Columbus, OH 43229-1 183 

Phone — 614.888.8320 

Fax — 614.847.1828 

Web Site — www.nationalboard.org 



Certificates of Authorization for Accreditation Programs 

Any organization seeking an accredited program may apply to the National Board to obtain a 

Certificate of Authorization for the requested scope of activities. A confidential review shall be 

conducted to evaluate the organization's quality system. Upon completion of the evaluation, 

a recommendation will be made to the National Board regarding issuance of a Certificate of 

Authorization. 

Certificate of Authorization scope, issuance, and revisions for National Board accreditation 
programs are specified in the applicable National Board procedures. When the quality system 
requirements of the appropriate accreditation program have been met, a Certificate of 
Authorization and appropriate National Board symbol stamp shall be issued. 



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Part 2 — Inspection 



All charts, graphs, tables, and other criteria that have been 
reprinted from the AS ME Boiler and Pressure Vessel Code, 
Sections I, IV, VIII, and X are used with the permission of 
the American Society of Mechanical Engineers. All Rights 
Reserved. 



NATIONAL BOARD INSPECTION CDDE • PART 2 — INSPECTION 



PART 2 — INSPECTION 
TABLE OF CONTENTS 



Section 1 General Requirements for Inservice Inspection of Pressure-Retaining Items 13 

1 .1 Scope 14 

1 .2 Administration 14 

1.3 Reference to Other Codes and Standards 14 

1 .4 Personnel Safety 14 

1 .4.1 Personal Safety Requirements for Entering Confined Spaces 1 5 

1 .4.2 Equipment Operation 16 

1 .5 Inspection Activities 16 

1 .5.1 Inservice Inspection Activities 16 

1 .5.2 Pre-lnspection Activities 16 

1.5.3 Preparation for Internal Inspection 16 

1 .5.4 Post-Inspection Activities 1 7 

Section 2 Detailed Requirements for Inservice Inspection of Pressure-Retaining Items 19 

2.1 Scope 20 

2.2 Boilers 20 

2.2.1 Scope 20 

2.2.2 Service Conditions 20 

2.2.3 Pre-lnspection Activities 20 

2.2.4 Condition of Boiler Room or Boiler Location 20 

2.2.5 External Inspection 20 

2.2.6 Internal Inspection 21 

2.2.7 Evidence of Leakage 21 

2.2.8 Boiler Corrosion Considerations 21 

2.2.9 Waterside Deposits 22 

2.2.10 Inspection of Boiler Piping, Parts, and Appurtenances 23 

2.2.10.1 Boiler Piping 23 

2.2.10.2 Stays and Staybolts 23 

2.2.10.3 Flanged or Other Connections ...23 

2.2.10.4 Miscellaneous 23 

2.2.10.5 Gages 24 

2.2.10.6 Pressure Relief Devices 24 

2.2.10.7 Controls 24 

2.2.1 1 Records Review 25 

2.2.12 Description and Concerns of Specific Types of Boilers 25 

2.2.12.1 Watertube Boilers 25 

2.2.12.2 Kraft or Sulfate Black Liquor Recovery Boilers 26 

2.2.12.3 Thermal Fluid Heaters 28 

2.2.12.4 Waste Heat Boilers 30 

2.2.12.5 Cast-Iron Boilers 31 

2.2.12.6 Electric Boilers 32 

2.2.12.7 Fired Coil Water Heaters 32 

2.2.12.8 Fired Storage Water Heaters 32 

2.2.12.9 Firetube Boilers 33 

2.3 Pressure Vessels 35 

2.3.1 Scope 35 

2.3.2 Service Conditions 35 

2.3.3 External Inspection 36 

2.3.4 Internal Inspection 37 

2.3.5 Inspection of Pressure Vessel Parts and Appurtenances 38 



NATIONAL BOARD INSPECTION CODE • PART 2 — INSPECTION 



2.3.5.1 Gages 38 

2.3.5.2 Safety Devices 38 

2.3.5.3 Controls/Devices 38 

2.3.5.4 Records Review 38 

2.3.6 Description and Concerns of Specific Types of Pressure Vessels 39 

2.3.6.1 Deaerators 39 

2.3.6.2 Compressed Air Vessels 40 

2.3.6.3 Expansion Tanks 40 

2.3.6.4 Liquid Ammonia Vessels 41 

2.3.6.5 Inspection of Pressure Vessels with 

Quick-Actuating Closures 43 

2.4 Piping and Piping Systems 45 

2.4.1 Scope 45 

2.4.2 Service Conditions 45 

2.4.3 Assessment of Piping Design 45 

2.4.4 External Inspection of Piping 45 

2.4.5 Internal Inspection of Piping 46 

2.4.6 Evidence of Leakage 46 

2.4.7 Provisions for Expansion and Support 46 

2.4.8 Inspection of Gages, Safety Devices, and Controls 47 

2.4.8.1 Gages 47 

2.4.8.2 Safety Devices 47 

2.4.8.3 Quick43isconnect Coupling 47 

2.5 Pressure Relief Devices 47 

2.5.1 Scope 47 

2.5.2 Pressure Relief Device Data 47 

2.5.3 Conditions 48 

2.5.4 Inservice Inspection Requirements for Pressure Relief Devices 48 

2.5.5 Additional Inspection Requirements 49 

2.5.5.1 Boilers 49 

2.5.5.2 Pressure Vessels and Piping 49 

2.5.5.3 Rupture Disks 49 

2.5.6 Requirements for Shipping and Transporting 51 

2.5.7 Testing and Operational Inspection of Pressure Relief Devices 51 

2.5.8 Recommended Inspection and Test Frequencies for 

Pressure Relief Devices 53 

Section 3 Corrosion and Failure Mechanisms 57 

3.1 Scope 58 

3.2 General 58 

3.3 Corrosion 58 

3.3.1 Macroscopic Corrosion Environments 58 

3.3.2 Microscopic Corrosion Environments 59 

3.3.3 Control of Corrosion 60 

3.3.3.1 Process Variables 60 

3.3.3.2 Protection 60 

3.3.3.3 Material Selection 60 

3.3.3.4 Coatings 61 

3.3.3.5 Engineering Design 61 

3.3.3.6 Conclusion 61 

3.4 Failure Mechanisms 62 

3.4.1 Fatigue 62 

3.4.2 Creep 62 

3.4.3 Temperature Effects 62 

3.4.4 Hydrogen Embrittlement 62 



NATIONAL BOARD INSPECTION CODE " PART 2 — INSPECTION 



3.4.5 High Temperature Hydrogen Attack 63 

3.4.6 Hydrogen Damage 64 

3.4.7 Bulges and Blisters 64 

3.4.8 Overheating 64 

3.4.9 Cracks 65 

Section 4 Examinations, Test Methods, and Evaluations 67 

4.1 Scope 68 

4.2 Nondestructive Examination Methods (NDE) 68 

4.2.1 Visual 68 

4.2.2 Magnetic Particle 68 

4.2.3 Liquid Penetrant 69 

4.2.4 Ultrasonic 69 

4.2.5 Radiography 69 

4.2.6 Eddy Current 70 

4.2.7 Metal lographic 70 

4.2.8 Acoustic Emission 70 

4.3 Testing Methods 70 

4.3.1 Pressure Testing 70 

4.3.2 Leak Testing 71 

4.3.3 Evidence of Leakage in a Boiler 71 

4.4 Methods to Assess Damage Mechanisms and Inspection Frequency 

for Pressure-Retaining Items 72 

4.4.1 Scope 72 

4.4.2 General Requirements 73 

4.4.3 Responsibilities 73 

4.4.4 Remaining Service Life Assessment Methodology 73 

4.4.5 Data Requirements for Remaining Service Life Assessments 74 

4.4.6 Identification of Damage Mechanisms 75 

4.4.7 Determining Inspection Intervals 75 

4.4.7.1 Method for Estimating Inspection Intervals for 
Pressure-Retaining Items Subject to Erosion 

or Corrosion 75 

4.4.7.2 Method for Estimating Inspection Intervals 

for Exposure to Corrosion 76 

4.4.7.3 Estimating Inspection Intervals for Pressure-Retaining 
Items Where Corrosion Is Not a Factor 79 

4.4.8 Evaluating Inspection Intervals of Pressure-Retaining Items 

Exposed to Inservice Failure Mechanisms 79 

4.4.8.1 Exposure to Elevated Temperature (Creep) 79 

4.4.8.2 Exposure to Brittle Fracture 80 

4.4.8.3 Evaluating Conditions That Cause 
Bulges/Blisters/Laminations 80 

4.4.8.4 Evaluating Crack4_ike Indications in Pressure- 
Retaining Items 80 

4.4.8.5 Evaluating Exposure of a Pressure-Retaining Item To 

Fire Damage 81 

4.4.8.6 Evaluating Exposure of Pressure-Retaining Items To 

Cyclic Fatigue 82 

4.4.8.7 Evaluating Pressure-Retaining Items Containing Local 

Thin Areas 82 

4.5 Risk-Based Inspection Assessment Programs 83 

4.5.1 Scope 83 

4.5.2 Definitions 83 

4.5.3 General 83 



NATIONAL BDARD INSPECTION CODE • PART 2 — INSPECTION 

4.5.4 Considerations 84 

4.5.5 Key Elements of an RBI Assessment Program 84 

4.5.6 RBI Assessment 85 

4.5.6.1 Probability of Failure 85 

4.5.6.2 Consequence of Failure 85 

4.5.6.3 Risk Evaluation 85 

4.5.6.4 Risk Management 86 

4.5.7 Jurisdictional Relationships 86 

Section 5 Stamping, Documentation, and Forms 87 

5.1 Scope 88 

5.2 Replacement of Stamping During Inservice Inspection 88 

5.2.1 Authorization 88 

5.2.2 Replacement of Stamped Data 88 

5.2.3 Reporting 88 

5.3 National Board Inspection Forms 88 

5.3.1 Scope 88 

5.3.2 Replacement of Stamped Data Form (NB-1 36) 89 

5.3.3 New Business or Discontinuance of Business Form (NB-4) 91 

5.3.4 Boiler or Pressure Vessel Data Report Form (NB-5) 93 

5.3.5 Boiler-Fired Pressure Vessels Report of Inspection Form (NB-6) 95 

5.3.6 Pressure Vessels Report of Inspection Form (NB-7) 97 

5.3.7 Report of Fitness For Service Assessment Form (NB-403) 99 

5.3.7.1 Guide For Completing Fitness For Service 

Assessment Reports 101 

Section 6 Supplements 103 

6.1 Scope 104 

Supp. 1 Steam Locomotive Firetube Boiler Inspection and Storage 104 

51 .1 Scope 104 

51.2 Special Jurisdictional Requirements 104 

51.3 Federal Railroad Administration (FRA) 105 

51.4 Locomotive Firetube Boiler Inspection 105 

51.4.1 Inspection Methods 105 

51.4.2 Inspection Zones 106 

51 .4.2.1 Riveted Seams and Rivet Heads 106 

51.4.2.2 Welded and Riveted Repairs 106 

51.4.2.3 Boiler Shell Course 107 

51 .4.2.4 Dome and Dome Lid 107 

51 .4.2.5 Mudring 107 

51 .4.2.6 Flue Sheets 107 

51 .4.2.7 Flanged Sheets 108 

51 .4.2.8 Stayed Sheets 108 

51 .4.2.9 Staybolts "!"l08 

51 .4.2.1 Flexible Staybolts and Sleeves 1 09 

51 .4.2.11 Girder Stay and Crown Bars 110 

51 .4.2.1 2 Sling Stays 110 

51 .4.2.1 3 Crown Stays and Expansion Stays 1 1 1 

51 .4.2.14 Diagonal and Gusset Braces 111 

51 .4.2.1 5 Flues 112 

S1 .4.2.1 6 Superheater Units and Header 1 12 

S1 .4.2.1 7 Arch Tubes, Water Bar Tubes, and Circulators 112 

SI .4.2.1 8 Thermic Syphons 113 

S1 .4.2.1 9 Firebox Refractory 113 



NATIONAL BOARD INSPECTION CODE • PART 2 — INSPECTION 



51.4.2.20 Dry Pipe 113 

51 .4.2.21 Throttle and Throttle Valve 113 

51 .4.2.22 Screw-Type Washout Plugs, Holes, and Sleeves 114 

51 .4.2.23 Handhole Washout Doors 114 

51 .4.2.24 Threaded and Welded Attachment Studs 1 1 4 

51.4.2.25 Fusible Plugs 115 

51 .4.2.26 Water Glass, Water Column, and Cage Cocks 1 1 5 

51 .4.2.27 Steam Pressure Gage 115 

51 .4.2.28 Boiler Fittings and Piping 115 

51 .4.2.29 Boiler Attachment Brackets 116 

51.4.2.30 Fire Door 116 

51 .4.2.31 Crates and Grate Operating Mechanism 1 1 6 

51.4.2.32 Smokebox 116 

51 .4.2.33 Smokebox Steam Pipes 1 1 7 

51 .4.2.34 Ash Pan and Fire Pan 1 1 7 

S1 .5 Guidelines for Steam Locomotive Storage 1 1 7 

51 .5.1 Storage Methods 1 1 7 

51.5.2 Wet Storage Method 118 

51.5.3 Dry Storage Method 118 

51.5.4 Recommended General Preservation Procedures 119 

SI .5.5 Use of Compressed Air to Drain Locomotive Components 1 22 

S1 .5.6 Return to Service 122 

Supp. 2 Historical Boilers 124 

52.1 Scope 124 

52.2 Introduction 124 

52.3 Responsibilities 124 

52.4 General Inspection Requirements 124 

52.4.1 Pre-lnspection Requirements 124 

52.4.2 Post-Inspection Activities 125 

52.4.3 Boiler Operators 125 

52.4.4 Examinations and Tests 126 

52.4.4.1 Nondestructive Examination Methods 126 

52.4.4.2 Testing Methods 126 

52.5 Specific Examination andTest Methods 126 

52.5.1 Specific Examination Methods 126 

52.5.2 Visual Examination 126 

52.5.2.1 Preparation for Visual Inspection 126 

52.5.2.2 Visual Examination Requirements 127 

52.5.3 Ultrasonic Examination 127 

52.5.4 Liquid Penetrant Examination 127 

52.5.5 Magnetic Particle Examination 127 

52.6 Specific Testing Methods 127 

52.6.1 Hydrostatic Pressure Testing 127 

52.6.2 Ultrasonic Thickness Testing 128 

52.7 Inspections 128 

52.7.1 Inservice Inspections 128 

52.7.2 Inservice Inspection Documentation 129 

52.7.3 Inspection Intervals 129 

52.7.3.1 Initial Inspection 129 

52.7.3.2 Subsequent Inspections 129 

52.8 Safety Devices — General Requirements 1 30 

52.8.1 Safety Valves 130 

52.8.2 Gage Glass 131 

52.8.3 Try-Cocks 131 

6 



NATIONAL BOARD INSPECTION CODE • PART 2 — INSPECTION 



52.8.4 Fusible Plug 131 

52.8.5 Pressure Gage 131 

S2.9 Appurtenances - Piping, Fittings, and Valves 132 

S2.9.1 Piping, Fittings, and Valve Replacements 132 

52.10 Maximum Allowable Working Pressure (MAWP) 132 

52.10.1 Strength 132 

52.10.2 Rivets 133 

52.10.3 Cylindrical Components 133 

52.10.4 Stayed Surfaces 140 

S2. 10.4.1 Staybolts 140 

52.10.5 Construction Code 140 

52.10.6 Nomenclature 140 

52.10.7 Limitations 143 

52.11 Boiler Inspection Guideline 143 

52.12 Initial Boiler Certification Report Form 148 

52.13 Guidelines for Historical Boiler Storage 148 

52.13.1 Storage Methods 148 

52.13.1.1 Wet Storage Method 148 

52.13.1.2 Dry Storage Method 149 

52.1 3.2 Recommended General Preservation Procedures 1 50 

52.1 3.3 Use of Compressed Air to Drain Historical Boiler Components 1 52 

52.13.4 Return to Service 152 

52.14 Safety Procedures 1 53 

52.14.1 Experience 1 53 

52.14.2 Stopping Engine in an Emergency 154 

52.14.3 Water Glass Breakage 154 

52.14.4 Runaway Engine and Governor Over Speed 1 55 

52.14.5 Killing a Fire 155 

52.14.6 Injector Problems 155 

52.14.7 Foaming or Priming Boiler 1 57 

52.14.8 Handhole Gasket Blows Out 157 

52.14.9 Tube Burst 158 

52. 14. 10 Leaking Valves 158 

52.14.1 1 Broken Pipes 158 

52.1 4.1 2 Safety Valve Problems 158 

52.14.13 Safety Valve Opens but will not Close 158 

52.14.14 Leaking Pipe Plugs 159 

52. 14.15 Melted Grates 159 

Supp. 3 Inspection of Graphite Pressure Equipment 1 63 

53.1 Scope 163 

53. 2 Application 163 

53. 3 Operations 163 

53. 4 Inservice Inspection 163 

Supp. 4 Inspection of Fiber4^einforced Thermosetting Plastic Pressure Equipment 1 65 

54.1 Scope 165 

54.2 Inservice Inspection 165 

54.3 General 165 

54.4 Visual Examination 165 

54.5 Inspector Qualifications 166 

54.6 Assessment of Installation 166 

54.6.1 Preparation 166 

54.6.2 Leakage 167 

54.6.3 Tools 167 



NATIONAL BOARD INSPECTION CODE • PART Z — INSPECTION 



54.7 External Inspection 167 

54.7.1 Insulation or Other Coverings 167 

54.7.2 Exposed Surfaces 167 

54.7.3 Structural Attachments 168 

54.8 Internal Inspection 168 

54.8.1 General 168 

54.8.2 Specific Areas of Concern 168 

54.9 Inspection Frequency 168 

54.9.1 Newly Installed Equipment 169 

54.9.2 Previously Repaired or Altered Equipment 1 69 

S4.10 Photographs of Typical Conditions 1 70 

Supp. 5 Inspection of Yankee Dryers (Rotating Cast-iron Pressure Vessels) with 

Finished Shell Outer Surfaces 186 

55.1 Scope I 86 

55.2 Assessment of Installation 1 86 

55.2.1 Determination of Allowable Operating Parameters 1 88 

55.2.2 Adjusting the Maximum Allowable Operating Parameters of 
the Yankee Dryer Due to a Reduction in Shell Thickness from 
Grinding or Machining 189 

55.2.3 Documentation of Shell Thickness and Adjusted Maximum 
Allowable Operating Parameters 1 90 

55.3 Causes of Deterioration and Damage 190 

55.3.1 Local Thinning 190 

55.3.2 Cracking 191 

55.3.2.1 Through Joints and Bolted Connections 191 

55.3.2.2 Through-Wall Leakage 191 

55.3.2.3 Impact From Objects Passing Through The Yankee/ 
Pressure Roll Nip 192 

55.3.2.4 Stress Magnification Around Drilled Holes 1 92 

55.3.2.5 Thermal Stress and/or Micro-Structural Change From 
Excessive Local Heating and Cooling 192 

55.3.2.6 Joint Interface Corrosion 192 

55.3.2.7 Stress-Corrosion Cracking of Structural Bolts 1 93 

55.3.3 Corrosion 193 

55.4 Inspections 193 

55.5 Nondestructive Examination 193 

55.6 Pressure Testing 194 

Supp. 6 Continued Service and Inspection of DOT Transport Tanks 195 

56.1 Scope 195 

56.2 Terminology 195 

56.3 Administration 195 

56.4 Inspection 195 

56.4.1 Scope 195 

56.4.2 General Requirements for Inspectors 195 

56.4.3 Registration of Inspectors 196 

56.4.4 Qualifications of Inspectors 196 

56.4.5 Codes of Construction 196 

56.4.6 Inspector Duties for Continued Service Inspections 1 96 

56.4.6.1 Inspector Duties for Continued Service Inspection 

of Cargo Tanks 197 

56.4.6.2 Inspector Duties for Continued Service Inspection 

of PortableTanks 197 

56.4.6.3 Inspector Duties for Continued Service Inspections 



NATIONAL BOARD INSPECTION CODE • PART Z INSPECTION 



of Ton Tanks 198 

S6.4.7 Continued Service, Inspection for DOT Transport Tanks Scope 198 

56.4.7.1 Administration 198 

56.4.7.2 Inspection and Test Required Frequencies 1 98 

56.4.7.3 External Visual and Pressure Tests 1 98 

56.4.7.4 Leak Tightness Testing of Transport Tanks 198 

56.4.7.4.1 Cargo Tanks 198 

56.4. 7.4.2 Portable Tanks 199 

56.4.7.4.3 Ton Tanks 199 

56.4.7.4.4 Leak Tightness Testing of Valves 199 

56. 4. 7. 4.4.1 Cargo Tanks 199 

56. 4. 7.4.4.2 PortableTanks 199 

56.4. 7.4.4.3 Ton Tanks 200 

56.4.7.5 Leak Tightness Testing of Safety Relief Devices 200 

56.4.7.5.1 Cargo Tanks 200 

56.4.7.5.2 PortableTanks 200 

56.4.7.5.3 Ton Tanks 201 

56.4.7.6 Testing of Miscellaneous Pressure Parts 201 

56.4.7.6.1 Cargo Tanks 201 

56.4. 7.6.2 Portable Tank 201 

56.4.7.6.3 Ton Tanks 201 

56.4.7.7 Acceptance Criteria 201 

56.4.7.8 Inspection Report 202 

56.4. 7.8.1 Cargo Tanks 202 

56.4. 7.8.2 PortableTanks 202 

56.4. 7.8.3 Ton Tanks 202 

56.5 Stamping and Record Requirements for DOT Transport Tanks in 

Continued Service 202 

56.5.1 General 202 

56.5.2 Stamping 202 

56.5.3 Owner or User Required Records For Cargo Tanks 203 

56.5.3.1 Reporting Requirements by the Owner or User of 

Tests and Inspections of DOT Specification Cargo Tanks 205 

56.5.3.2 DOT Marking Requirements for Test and Inspections 

of DOT Specification Cargo Tanks 205 

56.5.4 Owner or User Required Records for Portable Tanks 205 

56.5.4.1 Reporting of Periodic and Intermediate Periodic 
Inspection and Tests of DOT Specification 
PortableTanks 206 

56. 5.4.2 Marking Requirements for Periodic and Intermediate 
Inspection and Test for IM or UN PortableTanks 206 

56.5.4.3 DOT Marking Requirements for Periodic and 
Intermediate Inspection and Tests of DOT 
Specification 51, 56, 57, or 60 PortableTanks 206 

56.5.5 Owner or User Required Reports for DOT Specification 1 06A 

and DOT 1 10A Ton Tanks 207 

56.5.5.1 Reporting of Inspection and Tests for DOT 
Specification 1 06A and DOT 1 1 0A Ton Tanks 207 

56.5.5.2 DOT Marking Requirements for Test and Inspection 

of DOT Specification 1 06A and 1 1 0A Ton Tanks 207 

56.6 Corrosion and Failure Mechanisms in Transport Tanks 208 

56.6.1 Scope 208 

56.6.2 General 208 

56.6.3 Internal and/or External Corrosion 208 

S6.6.3.1 Types of Corrosion 208 



NATIONAL BOARD INSPECTION CODE • PART 2 — INSPECTION 



S6.6.4 Failure Mechanisms 210 

56.7 Classification Boundaries 212 

56.8 Pressure, Temperature, and Capacity Requirements for Transport Tanks 212 

56.9 Reference to Other Codes and Standards 212 

56.10 Conclusion 213 

56.1 1 Personnel Safety and Inspection Activities 213 

56.12 Transport Tank Entry Requirements 214 

56.12.1 Pre-lnspection Activities 214 

56.12.2 Preparation for Internal Inspection 215 

56.12.3 Post4nspection Activities 216 

56.13 Inspection and Tests of Cargo Tanks 216 

56.13.1 Visual External Inspection 216 

56.13.2 Inspection of Piping, Valves, and Manholes 219 

56.1 3.3 Inspection of Appurtenances and Structural Attachments 220 

56.13.4 Visual Internal Inspection 221 

56.13.5 Lining Inspections 221 

56.13.6 Pressure Tests 223 

56. 13.6.1 Hydrostatic or Pneumatic Test Method 224 

56. 13.6.2 Pressure Testing Insulated Cargo Tanks 225 

56. 13.6.3 Pressure Testing Cargo Tanks Constructed of 

Quenched and Tempered Steels 225 

56.1 3.6.4 Pressure Testing Cargo Tanks Equipped with a 

Heating System 226 

56. 13.6.5 Exceptions to Pressure Testing 226 

56.13.6.6 Acceptance Criteria 226 

56.13.6.7 Inspection Report 226 

56.13.7 Additional Requirements for MC 330 and MC 331 Cargo Tanks 227 

56.13.8 Certificates and Reports 228 

56.13.9 Leakage Test 228 

56. 13.10 New or Replaced Delivery Hose Assemblies 231 

56.13.10.1 Thickness Testing 231 

56.1 3.1 0.2 Testing Criteria 231 

56.13.10.3 Thickness Requirements 232 

56.13.1 1 Cargo Tanks That No Longer Conform to the Minimum Thickness 
Requirements in Tables S6.1 3.1 -a and S6.1 3.1 -b 232 

56.13.1 1 .1 Minimum Thickness for 400 Series Cargo Tanks 233 

56.13.11.2 DOT 406 Cargo Tanks 233 

56.13.11.3 DOT 407 Cargo Tanks 234 

56.13.11.4 DOT 412 Cargo Tanks 235 

56.14 Inspection and Tests of Portable Tanks 239 

56.14.1 Periodic Inspection andTest 240 

56.14.2 Intermediate Periodic Inspection andTest 240 

56.14.3 Internal and External Inspections 240 

56.14.4 Exceptional Inspection andTest 241 

56.14.5 Internal and External Inspection Procedure 241 

56.14.6 Pressure Tests Procedures for Specification 51, 57, 60, IM or UN 
Portable Tanks 242 

56.14.6.1 Specification 57 Portable Tanks 242 

56.14.6.2 Specification 51 or 56 Portable Tanks 243 

56.14.6.3 Specification 60 Portable Tanks 244 

56.14.6.4 Specification IM or UN PortableTanks 244 

56.14.7 Inspection andTest Markings for IM or UN PortableTanks 245 

56.14.8 Inspection andTest Markings for Specification DOT 51, 56, 

57, or 60 246 

56.14.9 Record Retention 246 

i a 



NATIONAL BOARD INSPECTION CODE - PART Z — INSPECTION 

56.15 General Requirements for DOT Specification 106Aand 11 OA Tank 

Cars (Ton Tanks) 246 

56.15.1 Special Provisions for Ton Tanks .."."247 

56.15.2 Visual Inspection of Ton Tanks ..........249 

56.1 5.3 Inspection and Tests of DOT Specification 1 06A and 

DOT Specification 11 OA Ton Tanks 249 

56.1 5.3.1 Air Tests !!!!!!!!!!!!!!!!!!!! 250 

56.1 5.3.2 Pressure Relief Device Testing 250 

56.15.3.3 Rupture Discs and Fusible Plugs 250 

56.1 5.3.4 Successful Completion of the Periodic Retesting 250 

56.1 5.3.5 Exemptions to Periodic Hydrostatic Retesting 251 

56.15.3.6 Record of Retest Inspection 251 

56.15.4 Stamping Requirements of DOT 106Aand DOT 11 OA Ton Tanks'"!.' 251 

56.16 Definitions 252 

Supp.7 Inspection of Pressure Vessels in Liquefied Petroleum Gas (LPG) Service 259 

57.1 Scope 259 

57.2 Prednspection Activities 259 

57.3 Inservice Inspection for Vessels in LP Gas Service !!!!!!!!!!!!!!!!!!!!!! 259 

S7.3.1 Nondestructive Examination (NDE) !.!!. 259 

57.4 External Inspection 260 

57.5 Internal Inspection 260 

57.6 Leaks 

57.7 Fire Damage 260 

57.8 Acceptance Criteria 261 

57.8.1 Cracks 261 

57.8.2 Dents ' """"" 2 61 

S7.8.3 Bulges !!!!!!!!!!!!!!!!!!!!!!!!!!!!! 262 

57.8.4 Cuts or Gouges !!!!!!!!!!!..!262 

57.8.5 Corrosion 262 

Section 7 NBIC Policy for Metrication 263 

7.1 General or/1 

-, ~ n . , „ . , 264 

7.2 Equivalent Rationale 264 

7.3 Procedure for Conversion 264 

7.4 Referencing Tables 265 

Section 8 Preparation of Technical Inquiries to the National Board Inspection Code 

Committee 269 

8.1 Introduction 27n 

8.2 Inquiry Format 270 

8.3 Code Revisions or Additions !!!!!.!!!!!! 271 

8.4 Code Interpretations 271 

8.5 Submittals •■••■-••■• 

Section 9 Glossary of Terms 273 

9.1 Definitions " 274 

Section 10 NBIC Approved Interpretations 277 

10.1 Scope """" 27H 

10.2 Index of Interpretations 278 

1 0.3 Subject Index of Interpretations !!!!!!!!!!!!!! 282 

Section 11 Index 2 or 



1 i 



N 



ATIDNAL BOARD INSPECTION CODE • PART 2 — INSPECTION 



1 Z 



Insert 

Section 1 
Tab 

Here 



■■■■■■■I 



'•.'-■ I 
If i 




Part 2, Sectidn 1 

Inspection — General Requirements 
For Inservice Inspection of 
Pressure-Retaining Items 



1 3 



NATIONAL BOARD INSPECTION CODE • PART 2 



INSPECTION 



PART 2, SECTION 1 
ISPECTfON — GENERAL REQUIREMENTS FOR iNSERVICE 
INSPECTION OF PRESSURE-RETAINING ITEMS 



1.1 



SCOPE 



This section provides general guidelines and 
requirements for conducting inservice inspec- 
tion of pressure-retaining items. Appropriately, 
this Section includes precautions for the safety 
of inspection personnel. The safety of the public 
and the Inspector is the most important aspect 
of any inspection activity. 



1.2 



ADMINISTRATION 



Jurisdictional requirements describe the fre- 
quency, scope, type of inspection, whether 
internal, external, or both, and type of docu- 
mentation required for the inspection. The 
Inspector shall have a thorough knowledge 
of jurisdictional regulations where the item is 
installed, as jurisdictional or regulatory inspec- 
tion requirements do vary. 



1.3 REFERENCE TO OTHER CODES 

AND STANDARDS 

Other existing inspection codes, standards, and 
practices pertainingto the inservice inspection 
of pressure-retaining items can provide use- 
ful information and references relative to the 
inspection techniques listed in this Part. Some 
examples are as follows: 



National Board Bulletin 
Classic Articles Series 



National Board 



b) American Society of Mechanical Engineers 

— ASME Boiler and Pressure Vessel Code 
Section V (Nondestructive Examination) 

c) American Society of Mechanical Engineers 

— ASME Boiler and Pressure Vessel Code 
Section VI (Recommended Rules for the 
Care and Operation of Heating Boilers) 



d) American Society of Mechanical Engineers 

— ASME Boiler and Pressure Vessel Code 
Section VII (Recommended Guidelines for 
the Care of Power Boilers) 

e) American Society of Mechanical Engineers 

— ASME B31C (Manual for Determining 
the Remaining Strength of Corroded Pipe- 
lines) 



f) American Petroleum Institute 
Inspection of Pressure Vessels 



g) 



API 572, 



American Petroleum Institute — API 574, 
Inspection Practices for Piping System 
Components 



h) American Petroleum Institute 
Fitness-For-Service 



API 579 



i) ASME CRTD Volume 41 , Risk-Based Inspec- 
tion for Equipment Life Management: An 
Application Handbook 

j) API Recommended Practice 580, Risk- 
Based Inspection 

k) API Publication 581 , Base Resource Docu- 
ment on Risk-Based Inspection 



1.4 PERSONNEL SAFETY 

a) Personnel safety is the joint responsibility 
of the owner or user and the Inspector. All 
applicable safety regulations shall be fol- 
lowed. This includes federal, state, regional, 
and/or local rules and regulations. Owner 
or user programs, safety programs of the 
Inspector's employer, or similar standards 
also apply. In the absence of such rules, 
prudent and generally accepted engineer- 



1 4 



NATIONAL BOARD INSPECTION CODE • PART Z — INSPECTION 



ing safety procedures satisfactory to the 
Inspector shall be employed by the owner 
or user. 

b) Inspectors are cautioned that the operation 
of safety devices involve the discharge of 
fluids, gases, or vapors. Extreme caution 
should be used when working around 
these devices due to hazards to personnel. 
Suitable hearing protection should be used 
during testing because extremely high noise 
levels can damage hearing. 

c) Inspectors shall take all safety precautions 
when examining equipment. Proper per- 
sonal protective equipment shall be worn, 
equipment shall be locked out, blanked off, 
decontaminated, and confined space entry 
permits obtained before internal inspec- 
tions are conducted. In addition, inspectors 
shall comply with plant safety rules associ- 
ated with the equipment and area in which 
they are inspecting. Inspectors are also 
cautioned that a thorough decontamination 
of the interior of vessels is sometimes very 
hard to obtain and proper safety precau- 
tions must be followed to prevent contact 
or inhalation injury with any extraneous 
substance that may remain in the tank or 
vessel. 



1.4.1 PERSONAL SAFETY 

REQUIREMENTS FOR ENTERING 
CONFINED SPACES 

a) No pressure-retaining item shall be entered 
until it has been properly prepared for in- 
spection. The owner or user and Inspector 
shall jointly determine that pressure-retain- 
ing items may be entered safely. This shall 
include: 

1 ) Recognized hazards associated with en- 
try into the object have been identified 
by the owner or user and are brought 
to the attention of the Inspector, along 
with acceptable means or methods for 
eliminating or minimizing each of the 
hazards; 



2) Coordination of entry into the object 
by the Inspector and owner or user 
representative(s) working in or near the 
object; 

3) Personal protective equipment required 
to enter an object, shall be used. This 
may include, among other items, pro- 
tective outer clothing, gloves, respira- 
tory protection, eye protection, foot 
protection and safety harnesses. The 
Inspector shall have the proper training 
governing the selection and use of any 
personal protective clothing and equip- 
ment necessary to safely perform each 
inspection. Particular attention shall be 
afforded respiratory protection if the 
testing of the atmosphere of the object 
reveals any hazards; 

4) Completing and posting of confined 
space entry permits, as applicable; 
and 

5) An effective energy isolation program 
(lock out and/or tag out) is in place and 
in effect that will prevent the unex- 
pected energizing, start up, or release 
of stored energy. 

b) The Inspector shall determine that a safe 
atmosphere exists before entering the pres- 
sure-retaining item. The atmosphere shall 
be verified by the owner or user as directed 
by the Inspector. 

1) The oxygen content of the breathable 
atmosphere shall be between 19.5% 
and 23.5%. 

2) If any flammable or combustible materi- 
als are present in the atmosphere they 
shall not exceed 10% of their lower ex- 
plosive limit (LEL) or lower flammable 
limit (LFL). 

3) The Inspector shall not enter an area if 
toxic, flammable or inert gases, vapors 
or dusts are present and above accept- 
able limits. 



1 5 



NATIDNAL BDARD INSPECTION CODE • PART Z — INSPECTION 



1.4.2 



EQUIPMENT OPERATION 



The Inspector shall not operate owner or user 
equipment. Operation shall be conducted only 
by competent owner or user employees familiar 
with the equipment and qualified to perform 
such tasks. 



1.5 



INSPECTION ACTIVITIES 



A proper inspection of a pressure-retaining 
item requires many pre-inspection planning 
activities including: safety considerations, an 
inspection plan that considers the potential 
damage mechanisms, selection of appropri- 
ate inspection methods, and awareness of 
the jurisdictional requirements. This section 
describes pre-inspection and post-inspection 
activities applicable to all pressure-retaining 
items. Specific inspection requirements for 
pressure-retaining items are identified in 2.2 for 
Boilers, 2.3 for Pressure Vessels, 2.4 for Piping 
and Piping Systems, and 2.5 for Pressure Relief 
Devices. 



1.5.1 INSERVICE INSPECTION 

ACTIVITIES 

Any defect or deficiency in the condition, op- 
erating, and maintenance practices of a boiler, 
pressure vessel, piping system, and pressure 
relief devices noted by the Inspector shall be 
discussed with the owner or user at the time 
of inspection and recommendations made for 
the correction of such defect or deficiency shall 
be documented. Use of a checklist to perform 
inservice inspections is recommended. 



2) Current jurisdictional inspection certifi- 
cate; 

3) ASME Code Symbol Stamping or mark 
of code of construction; 

4) National Board and/or jurisdiction reg- 
istration number; 

5) Operating conditions and normal con- 
tents of the vessel (discuss any unique 
hazards with the owner or user); 

6) Previous inspection report, operat- 
ing/maintenance logs and test records, 
and any outstanding recommendations 
from the previous inspection; 

7) Records of wall thickness checks, es- 
pecially where corrosion or erosion is 
a consideration; 

8) Review of repairs or alterations and any 
associated records for compliance with 
applicable requirements; and 

9) Observation of the condition of the 
overall complete installation, including 
maintenance and operation records. 

b) The following activities should be consid- 
ered to support the inspection: 

1) Removal of pressure gages or other 
devices for testing and calibration. 

2) Accessibility to inspect and test each 
pressure-retaining item and its appur- 
tenances. 



1.5.2 



PRE-INSPECTION ACTIVITIES 



Prior to conducting the inspection, a review 
of the known history of the pressure-retain- 
ing item and a general assessment of current 
conditions shall be performed. This shall 
include a review of information such as: 

1 ) Date of last inspection; 



1 .5.3 PREPARATION FOR INTERNAL 

INSPECTION 

The owner or user has the responsibility to 
prepare a pressure-retaining item for internal 
inspection. Requirements of occupational 
safety and health regulations (federal, state, 
local, or other), as well as the owner-user's 
own program and the safety program of the 



i 6 



NATIONAL BOARD INSPECTION CODE • PART 2 



INSPECTION 



Inspector's employer are applicable. The pres- 
sure-retaining item should be prepared in the 
following manner or as deemed necessary by 
the Inspector: 

a) When a vessel is connected to a common 
header with other vessels or in a system 
where liquids or gases are present, the 
vessel shall be isolated by closing, locking, 
and/or tagging stop valves in accordance 
with the owner's or user's procedures. When 
toxic or flammable materials are involved, 
additional safety precautions may require 
removing pipe sections or blanking pipe- 
lines before entering the vessel. The means 
of isolating the vessel shall be in compli- 
ance with applicable occupational safety 
and health regulations and procedures. For 
boilers or fired pressure vessels, the fuel 
supply and ignition system shall be locked 
out and/or tagged out, in accordance with 
the owner's or user's procedures. 

b) The vessel temperature shall be allowed to 
cool or warm at a rate to avoid damage to 
the vessel. When a boiler is being prepared 
for internal inspection, the water should not 
be withdrawn until it has been sufficiently 
cooled at a rate to avoid damage. 

c) The vessel shall be drained of all liquid 
and shall be purged of any toxic or flam- 
mable gases or other contaminants that 
were contained in the vessel. The continu- 
ous use of mechanical ventilation using a 
fresh air blower or fan may be necessary 
to maintain the vessel's atmosphere within 
acceptable, limits. During air purging and 
ventilation of vessels containing flammable 
gases, the concentration of vapor in air may 
pass through the flammable range before a 
safe atmosphere is obtained. All necessary 
precautions shall be taken to eliminate the 
possibility of explosion or fire. 

d) Items requested by the Inspector, such as 
manhole and hand hole plates, washout 
plugs, inspection plugs, and any other items 
shall be removed. 



e) The Inspector shall not enter a vessel until 
all safety precautions have been taken. 
The temperature of the vessel shall be such 
that the inspecting personnel will not be 
exposed to excessive heat. Vessel surfaces 
should be cleaned as necessary so as to 
preclude entrant exposure to any toxic or 
hazardous materials. 

f) If requested by the Inspector or required 
by regulation or procedure, a responsible 
attendant shall remain outside the vessel 
at the point of entry while the Inspector is 
inside and shall monitor activity inside and 
outside and communicate with the Inspec- 
tor as necessary. The attendant shall have a 
means of summoning rescue assistance, if 
needed, and to faci I itate rescue procedures 
for all entrants without personally entering 
the vessel. 

Note: If a vessel has not been properly pre- 
pared for an internal inspection, the Inspec- 
tor shall decline to make the inspection. 



1.5.4 POST-INSPECTION ACTIVSTSES 

a) During any inspections or tests of pressure- 
retaining items, the actual operating and 
maintenance practices should be noted by 
the Inspector and a determination made as 
to their acceptability. 

b) Any defects or deficiencies in the condition, 
operating, and maintenance practices of the 
pressure-retaining item shall be discussed 
with the owner or user at the time of in- 
spection and recommendations made for 
correction. Follow-up inspections should 
be performed as needed to determine if 
deficiencies have been corrected satisfac- 
torily. 

c) Documentation of inspection shall contain 
pertinent data such as description of item, 
classification, identification numbers, in- 
spection intervals, date inspected, type of 
inspection, and test performed, and any 



i v 



NATIONAL BOARD INSPECTION CODE • PART Z — INSPECTION 



other information required by the inspec- 
tion agency, jurisdiction, and/or owner-user. 
The Inspector shall sign, date, and note any 
deficiencies, comments, or recommenda- 
tions on the inspection report. The Inspector 
should retain and distribute copies of the 
inspection report, as required. 

d) The form and format of the inspection 
report shall be as required by the Jurisdic- 
tion. Where no Jurisdiction exists, forms 
NB-5, NB-6, or NB-7 (see 5.3) or any other 
form(s) required by the inspection agency or 
owner-user may be used as appropriate. 



1 B 



Insert 

Section 2 
Tab 

Here 





Part 2, Section 2 

Inspection — Detailed Requirements 
For Inservice Inspection of 
Pressure-Retaining Items 



1 9 



NATIONAL BOARD INSPECTION CODE • PART Z 



INSPECTION 



PART 2, SECTION 2 

INSPECTION — DETAILED REQUIREMENTS FOR 

INSERVICE INSPECTION OF PRESSURE-RETAINING ITEMS 



2.1 SCOPE 

a) This section describes general and detailed 
inspection requirements for pressure-retain- 
ing items to determine corrosion deterio- 
ration and possible prevention of failures 
for boilers, pressure vessels, piping, and 
pressure relief devices. 

b) Materials to be inspected shall be suitably 
prepared so surface irregularities will not be 
confused with or mask any defects. Material 
conditioning such as cleaning, buffing, wire 
brushing, or grinding may be required by 
procedure or, if requested, by the Inspec- 
tor. The Inspector may require insulation or 
component parts to be removed. 



2.2 BOILERS 



2.2.1 



SCOPE 



This section provides guidelines for external 
and internal inspection of boilers used to con- 
tain pressure. This pressure may be obtained 
from an external source or by the application 
of heat from a direct or indirect source or a 
combination thereof. 



2.2.2 



SERVICE CONDITIONS 



a) Boilers are designed for a variety of service 
conditions. The temperature and pressure at 
which they operate should be considered 
in establishing inspection criteria. This part 
is provided for guidance of a general na- 
ture. There may be occasions where more 
detailed procedures will be required. 

b) The condition of the complete installation, 
including maintenance and operation, can 



often be used by the Inspector as a guide 
in forming an opinion of the care given to 
the boiler. 

Usually the conditions to be observed by 
the Inspector are common to both power 
and heating boilers, however, where ap- 
propriate, the differences are noted. 



2.2.3 



PRE-INSPECTION ACTIVITIES 



A review of the known history of the boiler shall 
be performed. This shall include a review of 
information contained in 1 .5.2 and other items 
listed in 2.2.4 below. 



2.2.4 CONDITION OF BOILER ROOM 

OR BOILER LOCATION 

The general condition of the boiler room or 
boiler location should be assessed using ap- 
propriate jurisdictional requirements and 
overall engineering practice. Items that are 
usually considered are lighting, adequacy of 
ventilation for habitability, combustion air, 
housekeeping, personal safety, and general 
safety considerations. 



2.2.5 



EXTERNAL INSPECTION 



The external inspection of a boiler is made to 
determine if it is in a condition to operate safely. 
Some items to consider are: 

a) The boiler fittings, valves, and piping should 
be checked for compliance with ASME 
Code or other standards or equivalent re- 
quirements. Particular attention should be 
paid to pressure relief devices and other 
safety controls; 



2D 



NATIONAL BOARD INSPECTION CODE • PART 2 



INSPECTION 



b) Firing equipment controls; 

c) Adequacy of structure, boiler supports, and 
any associated support steel; 

d) Boiler casing should be free from cracks, 
combustion gas, or fluid leaks, excessive 
corrosion or other degradation that could 
interfere with proper operation; 

e) Soot blowers, valves, and actuating mecha- 
nisms; 

f) Gaskets on observation doors, access doors, 
drums, handhole and manhole covers and 
caps; 

g) Valves and actuators, either chains, motors, 
and/or handwheels; and 

h) Leakage of fluids or combustion gases. 



2.2.6 



INTERNAL INSPECTION 



a) When a boiler is to be prepared for internal 
inspection, the water shall not be with- 
drawn until the setting has been sufficiently 
cooled at a rate to avoid damage to the 
boiler as well as additional preparations 
identified in 1.4.1 and 1.5.3. 

b) The owner or user shall prepare a boi ler for 
internal inspection in the following man- 
ner: 

1) Before opening the manhole(s) and 
entering any part of the boiler that is 
connected to a common header with 
other boilers, the required steam or 
water system stop valves (including 
bypass) must be closed, locked out, 
and/or tagged in accordance with the 
owner-user's procedures, and drain 
valves or cocks between the two closed 
stop valves be opened. After draining 
the boiler, the blowoff valves shall be 
closed, locked out, and/or tagged out 
in accordance with the owner-user's 



procedures. Alternatively, lines may be 
blanked or sections of pipe removed. 
Blowoff lines, where practicable, shall 
be disconnected between pressure 
parts and valves. All drains and vent 
lines shall be open. 

2) The Inspector shall review all personnel 
safety requirements as outlined in 1.4 
prior to entry. 

Note: If a boiler has not been properly 
prepared for an internal inspection, 
the inspector shall decline to make the 
inspection. 



2.2.7 



EVIDENCE OF LEAKAGE 



a) It is not normally necessary to remove in- 
sulating material, masonry, or fixed parts 
of a boiler for inspection, unless defects 
or deterioration are suspected or are com- 
monly found in the particular type of boiler 
being inspected. Where there is evidence 
of leakage showing on the covering, the In- 
spector shall have the covering removed in 
order that a thorough inspection of the area 
may be made. Such inspection may require 
removal of insulating material, masonry, or 
fixed parts of the boiler. 

b) For additional information regarding a leak 
in a boiler or determining the extent of a 
possible defect, a leak test may be per- 
formed per 4.3.3. 



2.2.8 BOILER CORROSION 

CONSIDERATIONS 

a) Corrosion causes deterioration of the metal 
surfaces. It can affect large areas or it can 
be localized in the form of pitting. Isolated, 
shallow pitting is not considered serious if 
not active. 



2 1 



NATIONAL BOARD INSPECTION CODE • PART Z 



INSPECTION 



b) The most common causes of corrosion in 
boilers are the presence of free oxygen and 
dissolved salts in the feedwater. Where 
active corrosion is found, the Inspector 
should advise the owner or user to obtain 
competent advice regarding proper feed- 
water treatment. 

c) For the purpose of estimating the effect of 
severe corrosion over large areas on the safe 
working pressure, the thickness of the re- 
maining sound metal should be determined 
by ultrasonic examination or by drilling. 

d) Grooving is a form of metal deterioration 
caused by localized corrosion and may be 
accelerated by stress concentration. This is 
especially significant adjacent to riveted 
joints. 

e) All flanged surfaces should be inspected, 
particularly the flanges of unstayed heads. 
Grooving in the knuckles of such heads is 
common since there is slight movement in 
heads of this design which causes a stress 
concentration. 

f) Some types of boilers have ogee or re- 
versed-flanged construction which is prone 
to grooving and may not be readily acces- 
sible for examination. The Inspector should 
insert a mirror through an inspection open- 
ing to examine as much area as possible. 
Other means of examination such as the 
ultrasonic method may be employed. 

g) Grooving is usually progressive and when 
it is detected, its effect should be carefully 
evaluated and corrective action taken. 

h) The fireside surfaces of tubes in horizontal 
firetube boilers usually deteriorate more 
rapidly at the ends nearest the fire. The 
Inspector should examine the tube ends to 
determine if there has been serious reduc- 
tion in thickness. The tube surfaces in some 
vertical tube boilers are more susceptible 
to deterioration at the upper ends when 
exposed to the heat of combustion. These 



k) 



tube ends should be closely examined to 
determine if there has been a serious re- 
duction in thickness. The upper tube sheet 
in a vertical "dry top" boiler should be 
inspected for evidence of overheating. 

Pitting and corrosion on the waterside sur- 
faces of the tubes should be examined. In 
vertical firetube boilers, excessive corrosion 
and pitting is often noted at and above the 
water level. 

The surfaces of tubes should be carefully 
examined to detect corrosion, erosion, 
bulges, cracks, or evidence of defective 
welds. Tubes may become thinned by 
high velocity impingement of fuel and ash 
particles or by the improper installation 
or use of soot blowers. A leak from a tube 
frequently causes serious corrosion or ero- 
sion on adjacent tubes. 

In restricted fireside spaces, such as where 
short tubes or nipples are used to join 
drums or headers, there is a tendency for 
fuel and ash to lodge at junction points. 
Such deposits are likely to cause corrosion 
if moisture is present, and the area should 
be thoroughly cleaned and examined. 



2.2.9 



WATERSIDE DEPOSITS 



a) All accessible surfaces of the exposed metal 
on the waterside of the boiler should be 
inspected for deposits caused by water 
treatment, scale, oil, or other substances. 
Oil or scale in the tubes of watertube boil- 
ers is particularly detrimental since this 
can cause an insulating effect resulting in 
overheating, weakening, possible metal 
fatigue, bulging, or rupture. 

b) Excessive scale or other deposits should 
be removed by chemical or mechanical 
means. 



22 



NATIONAL BOARD INSPECTION CODE • PART 2 



INSPECTION 



2.2.10 INSPECTION OF BOILER 
PIPING, PARTS, AND 
APPURTENANCES 



2.2.10.1 BOILER PIPING 

Piping should be inspected in accordance 
with 2.4. 



2.2.10.2 STAYS AND STAYBOLTS 



externally. Whenever possible, observation 
should be made from both sides, internally 
and externally, to determine whether con- 
nections are properly made to the boiler. 

b) All openings leading to external attach- 
ments, such as water column connections, 
low water fuel cut-off devices, openings in 
dry pipes, and openings to safety valves, 
should be examined to ensure they are free 
from obstruction. 



a) All stays, whether diagonal or through, 
should be inspected to determine whether 
or not they are in even tension. Staybolt 
ends and the stayed plates should be exam- 
ined to determine whether cracks exist. In 
addition, stayed plates should be inspected 
for bulging in the general area of the stay. 
Each staybolt end should be checked for 
excessive cold working (heading) and seal 
welds as evidence of a possible leakage 
problem. Stays or staybolts that are not 
in tension or adjustment should be re- 
paired. Broken stays or staybolts shall be 
replaced. 

b) The Inspector should test firebox staybolts 
by tapping one end of each bolt with a 
hammer and, where practicable, a hammer 
or other heavy tool should be held on the 
opposite end to make the test more effec- 
tive. An unbroken bolt should give a ring- 
ing sound while a broken bolt will give a 
hollow or non-responsive sound. Staybolts 
with telltale holes should be examined for 
evidence of leakage, which will indicate a 
broken or cracked bolt. Broken staybolts 
shall be replaced. 



2.2.10.3 FLANGED OR OTHER 
CONNECTIONS 

a) The manhole and reinforcing plates, as well 
as nozzles or other connections flanged or 
bolted to the boiler, should be examined 
for evidence of defects both internally and 



2.2.10.4 MISCELLANEOUS 

a) The piping to the water column should be 
carefully inspected to ensure that water 
cannot accumulate in the steam connec- 
tion. The position of the water column 
should be checked to determine that the 
column is placed in accordance with the 
original code of construction or jurisdic- 
tional requirements. 

b) The gas side baffling should be inspected. 
Absence of proper baffling or defective 
baffling can cause high temperatures and 
overheat portions of the boiler. The location 
and condition of combustion arches should 
be checked for evidence of flame impinge- 
ment, which could result in overheating. 

c) Any localization of heat caused by improper 
or defective installation or improper opera- 
tion of firing equipment shall be corrected 
before the boiler is returned to service. 

d) The refractory supports and settings should 
be carefully examined, especially at points 
where the boiler structure comes near the 
setting walls or floor, to ensure that deposits 
of ash or soot will not bind the boiler and 
produce excessive strains on the structure 
due to the restriction of movement of the 
parts under operating conditions. 

e) When tubes have been re-rolled or re- 
placed, they should be inspected for proper 
workmanship. Where tubes are readily ac- 



23 



NATIONAL BOARD INSPECTION CODE • PART 2 



INSPECTION 



cessible, they may have been over rolled. 
Conversely, when it is difficult to reach 
the tube ends, they may have been under 
rolled. 

f) Drums and headers should be inspected 
internally and externally for signs of leak- 
age, corrosion, overheating, and erosion. 
Inspect blowdown piping and connections 
for expansion and flexibility. Check header 
seals for gasket leakage. 

g) Soot blower mechanical gears, chains, pul- 
leys, etc., should be checked for broken 
or worn parts. Inspect supply piping to the 
soot blowers for faulty supports, leakage, 
and expansion and contraction provisions. 
Check design for proper installation to al- 
low for complete drainage of condensate, 
which may cause erosion. 

h) Valves should be inspected on boiler feed- 
water, blowdown, drain, and steam systems 
for gland leakage, operability, tightness, 
handle or stem damage, body defects, and 
general corrosion. 



2.2.10.5 GAGES 

a) Ensure that the water level indicated is cor- 
rect by having the gage tested as follows: 

1 ) Close the lower gage glass valve, then 
open the drain cock and blow the glass 
clear. 

2) Close the drain cock and open the 
lower gage glass valve. Water should 
return to the gage glass immediately. 

3) Close the upper gage glass valve, then 
open the drain cock and allow the wa- 
ter to flow until it runs clean. 

4) Close the drain cock and open the 
upper gage glass valve. Water should 
return to the gage glass immediately. 



5) If the water return is sluggish, the test 
should be discontinued. A sluggish 
response could indicate an obstruction 
in the pipe connections to the boiler. 
Any leakage at these fittings should be 
promptly corrected to avoid damage to 
the fittings or a false waterline indica- 
tion. 

b) Unless there is other information to assess 
its accuracy or reliability, all the pressure 
gages shall be removed, tested, and their 
readings compared to the readings of a cali- 
brated standard test gage or a dead weight 
tester. 

c) The location of a steam pressure gage 
should be noted to determine whether it is 
exposed to high temperature from an exter- 
nal source or to internal heat due to lack of 
protection by a proper siphon or trap. The 
Inspector should check that provisions are 
made for blowing out the pipe leading to 
the steam gage. 

d) The Inspector should observe the pressure 
gage reading during tests; for example, the 
reduction in pressure when testing the low 
water fuel cutoff control or safety valve 
on steam boilers. Defective gages shall be 
replaced. 



2.2.10.6 PRESSURE RELIEF DEVICES 

See 2.5 for the inspection of safety devices 
(pressure relief valves) used to prevent overpres- 
sure of boilers. 



2.2.10.7 CONTROLS 

a) Verify operation of low water protection de- 
vices by observing the blowdown of these 
controls or the actual lowering of boiler 
water level under carefully controlled con- 
ditions with the burner operating. This test 
should shut off the heat source to the boiler. 



24 



NATIONAL BOARD INSPECTION CODE • PART 2 — INSPECTION 



The return to normal condition such as the 
restart of the burner, the silencing of an 
alarm, or stopping of a feed pump should 
be noted. A sluggish response could indi- 
cate an obstruction in the connections to 
the boiler. 

b) The operation of a submerged low water 
fuel cutoff mounted directly in a steam 
boiler shell should be tested by lowering the 
boiler water level carefully. This should be 
done only after being assured that the water 
level gage glass is indicating correctly. 

c) On a high-temperature water boiler, it is 
often not possible to test the control by 
cutoff indication, but where the control is 
of the float type, externally mounted, the 
float chamber should be drained to check 
for the accumulation of sediment. 

d) In the event controls are inoperative or the 
correct water level is not indicated, the 
boiler shall be taken out of service until the 
unsafe condition has been corrected. 

e) Al I automatic low water fuel cutoff and wa- 
ter feeding devices should be examined by 
the Inspector to ensure that they are prop- 
erly installed. The Inspector should have 
the float chamber types of control devices 
disassembled and the float linkage and 
connections examined for wear. The float 
chamber should be examined to ensure that 
it is free of sludge or other accumulation. 
Any necessary corrective action shall be 
taken before the device is placed back into 
service. The Inspector should check that the 
operating instructions for the devices are 
readily available. 

f) Check that the following controls/devices 
are provided: 



1 



Each automatically-fired steam boiler 
is protected from over pressure by not 
less than two pressure operated con- 
trols, one of which may be an operating 
control. 



2.2.11 



Each automatically-fired hot-water 
boiler is protected from over-tempera- 
ture by not less than two temperature 
operated controls, one of which may 
be an operating control. 

Each hot-water boiler is fitted with a 
thermometer that will, at all times, in- 
dicate the water temperature at or near 
the boiler outlet. 



RECORDS REVIEW 



a) A review of the boiler log, records of main- 
tenance, and feedwater treatment should be 
made by the Inspector to ensure that regular 
and adequate tests have been made on the 
boiler and controls. 

b) The owner or user should be consulted re- 
garding repairs or alterations, if any, which 
have been made since the last inspection. 
Such repairs or alterations should be re- 
viewed for compliance with the jurisdic- 
tional requirements, if applicable. 



2.2.1 2 DESCRIPTION AND CONCERNS 

OF SPECIFIC TYPES OF BOILERS 

The following details are unique to specific 
type boilers and should be considered when 
performing inspections along with the general 
requirements as previously outlined. 



2.2.12.1 WATERTUBE BOILERS 

a) Typically constructed of drums, headers, 
and tubes, watertube boilers are used to 
produce steam or hot water commonly 
in large quantities. They range in size 
and pressure from small package units to 
extremely large field erected boilers with 
pressures in excess of 3000 psig (41.37 
MPa gage). These boilers may be fired by 
many types of fuels such as wood, coal, 



25 



NATIONAL BOARD INSPECTION CODE * PART Z — INSPECTION 



gas, oil, trash, and black liquor. Their size 
and type of construction poses mechanical 
and thermal cyclic stresses. 

b) There are many locations both internal and 
external where moisture and oxygen com- 
bine causing primary concern for corrosion. 
The fuels burned in watertube boilers may 
contain ash, which can form an abrasive 
grit in the flue gas stream. The abrasive ac- 
tion of the ash in high velocity flue gas can 
quickly erode boiler tubes. 

c) Unique parts associated with this type of 
construction such as casing, expansion 
supports, superheater, economizer, soot 
blowers, drums, headers, and tubes should 
be inspected carefully and thoroughly in 
accordance with 2.2. 



2.2.1 2.2 KRAFT OR SULFATE BLACK 

LIQUOR RECOVERY BOILERS 

a) Kraft or Sulfate Black Liquor Recovery 
boilers are used in the pulp and paper 
industry. Black liquor is a by-product of 
pulp processing. It contains organic and 
inorganic constituents concentrated to at 
least 58% solids for firing in the recovery 
boilers. The organic material that is dis- 
solved in the pulping process combusts, 
and the spent pulping chemicals form a 
molten pool in the furnace. The molten 
material, or "smelt," drains from the furnace 
wall through smelt spouts into a smelt dis- 
solving tank for recovery of the chemicals. 
Ultimately, the by-product of the recovery 
process is steam used for processing and 
power. Gas or oil auxilliary burners are 
used to start the self-sustaining black liquor 
combustion process and may be used to 
produce supplemental steam if sufficient 
liquor is not available. 

b) The recovery combustion process requires a 
reducing atmosphere near the furnace floor 
and an oxidizing atmosphere in the upper 
furnace for completion of combustion. 



Pressure parts within the furnace require 
protection from the reducing atmosphere 
and from sulfidation. The rate of corrosion 
within the furnace is temperature depen- 
dent. Boilers operating up to 900 psi (6.21 
MPa) typically have plain carbon steel 
steam generating tubes with pin studs ap- 
plied to the lower furnace to retain a pro- 
tective layer of refractory or "frozen" smelt. 
Above 900 psi (6.2 1 MPa) the lower furnace 
tubes will typically have a special corrosion 
protection outer layer. The most common 
is a stainless steel clad "composite tube." 
Other protection methods are corrosion re- 
sistant overlay welding, thermal or plasma 
spray coating, and diffusion coating. 

c) The unique hazard of these boilers is the 
potential for an explosion if water should 
be combined with the molten smelt. The 
primary source of water is from pressure 
part failure, permitting water to enter the 
furnace. The owner's inspection program is 
carefully developed and executed at appro- 
priate intervals to avoid pressure part failure 
that could admit water to the furnace. A 
second source of water is the liquor fuel. 

d) Permitting black liquor of 58% or lower 
solids content to enter the furnace can also 
result in an explosion. The black liquor fir- 
ing controls include devices that monitor 
and automatically divert the liquor from the 
furnace if solids content is 58% or lower. 

e) In addition to the general inspection re- 
quirements for all watertube-type boilers, 
particular awareness in the following areas 
is necessary: 

1 ) Furnace — the type and scope of wall, 
roof, and water screen tube inspection 
is dependent on materials of construc- 
tion, type of construction, and mode of 
boiler operation. In all cases, furnace 
wall opening tubes need inspection 
for thinning and cracking. The typical 
water-cooled smelt spout can admit 
, water to the furnace if the spout fails. 



26 



NATIONAL BOARD INSPECTION CODE • PART 2 



INSPECTION 



Common practice is to replace these 
spouts in an interval shorter than that 
in which failure is known to occur. 

2) Water — percentage of sol ids contained 
in the black liquor before entering the 
furnace shall be closely monitored. 
Verify that the black liquor firing system 
will automatically divert the liquor if 
solids drop to or below 58%. 

3) Corrosion/erosion — the potential 
consequences of corrosion or erosion 
(smelt-water explosion due to pres- 
sure-retaining part failure) requires a 
well planned and executed inspection 
program by the owner. Maintenance of 
boiler water quality is crucial to mini- 
mizing tube failure originating from the 
water side. 

4) Tubes — depending on type of con- 
struction, inspect for damage such as 
loss of corrosion protection, thinning, 
erosion, overheating, warping, elonga- 
tion, bulging, blistering, and misalign- 
ment. If floor tubes may have been 
mechanically damaged or overheated, 
clean the floor and perform the appro- 
priate type of inspection for suspected 
damage. Excursions in water treatment 
may result in scale and sludge on in- 
ternal surfaces, creating conditions of 
poor heat transfer and ultimately caus- 
ing tube cracks or rupture. 

5) Welds — leaks frequently originate at 
welds. The owner and repair agency 
should carefully plan and inspect all 
repair welds and seal welds that could 
admit water to the furnace. Tube butt 
welds that could admit water to the 
furnace should be examined by a 
volumetric NDE method acceptable to 
the inspector. Tube leaks at attachment 
welds may originate from the internal 
stress-assisted corrosion (SAC). Minor 
upsets in boiler water quality and im- 
proper chemical cleaning may initiate 
SAC. 



6) Emergency Response to Water Entering 
Furnace — operators of Kraft recovery 
boilers should have a plan to imme- 
diately terminate all fuel firing and 
drain water from the boiler if a tube is 
known or suspected to be leaking into 
the furnace. This system may be called 
"Emergency Shutdown Procedure" or 
"ESP." The inspector should confirm 
the ESP is tested and maintained such 
that it will function as intended and 
that operators will activate the system 
when a leak into the furnace occurs or 
is suspected. 

7) Overheating — tube rupture due to 
overheating from low water level may 
admit water to the furnace. The inspec- 
tor should verify a redundant low-wa- 
ter protection system is provided and 
maintained. 

f) Recommended procedures for inspection of 
black liquor recovery boilers are identified 
below: 

1 ) American Forest and Paper Association 
"Recovery Boiler Reference Manual 
for Owners and Operators of Kraft 
Recovery Boilers," sponsored by the 
Operations/Maintenance Subcommit- 
tee of the Recovery Boiler Committee, 
Volumes I, II, and III (current published 
editions). 

2) The Black Liquor Recovery Boiler 
Advisory Committee, Recommended 
Practices: 

a. Emergency Shutdown Procedure 
(ESP) and Procedure for Testing 
ESP 

b. Safe Firing of Black Liquor Recovery 
Boilers 

c. System for Black Liquor Boilers 

d. Safe Firing of Black Liquor in Black 
Liquor Recovery Boilers 



27 



NATIONAL BOARD INSPECTION CODE • PART 2 



INSPECTION 



e. Safe Firing of Auxiliary Fuel in Black 
Liquor Recovery Boilers 

f. Thermal Oxidation of Waste Streams 
in Black Liquor Recovery Boilers 

g. Instrumentation Checklist and Clas- 
sification Guide for Instruments 
and Control Systems used in the 
Operation of Black Liquor Recovery 
Boilers 

h. Recommended Guidelines for Per- 
sonnel Safety 

3) Technical Association of the Pulp and 
Paper Industry (TAPPI), Technical Infor- 
mation Papers: 

a. 0402-13, Guidelines for Specifi- 
cation and Inspection of Electric 
Resistance Welded (ERW) and 
Seamless Boiler Tube for Critical 
and Non-Critical Service 

b. 0402-1 5, Installation and Repair of 
Pin Studs in Black Liquor Recovery 
Boilers 

c. 0402-1 8, Ultrasonic Testing (UT) 
for Tube Thickness in Black Liquor 
Recovery Boilers 

1 . Part I: Guidelines for Accurate 
Tube Thickness Testing 

2. Part II: Default Layouts for 
Tube Thickness Surveys in 
Various Boiler Zones 

d. 0402-21, Ultrasonic Technician 
Performance Test for Boiler Tube 
Inspection 

e. 0402-30, Inspection for Cracking 
of Composite Tubes in Black Liquor 
Recovery Boilers 



f. 0402-31, Guidelines for Evaluat- 
ing the Quality of Boiler Tube Butt 
Welds with Ultrasonic Testing 

g. 0402-33, Guideline for Obtaining 
High Quality Radiographic Testing 
(RT) of Butt Welds in Boiler Tubes 



2.2.12.3 THERMAL FLUID HEATERS 
a) Design and Operating Features 

1 ) Many thermal fluid heaters are pressure 
vessels in which a synthetic or organic 
fluid is heated or vaporized. Some 
thermal fluid heaters operate at atmo- 
spheric pressure. The fluids are typically 
flammable, are heated above the liquid 
flash point, and may be heated above 
the liquid boiling point. The heaters are 
commonly direct-fired by combustion 
of a fuel or by electric resistance ele- 
ments. Heater design may be similar to 
an electric resistance heated boiler, to 
a firetube boiler or, more commonly, 
to a watertube boiler. Depending on 
process heating requirements, the 
fluid may be vaporized with a natural 
circulation, but more often, the fluid 
is heated and circulated by pumping 
the liquid. Use of thermal fluid heating 
permits heating at a high temperature 
with a low system pressure (600°F to 
700°F [316°C to 371 °C] at pressures 
just above atmospheric]. To heat water 
to those temperatures, would require 
pressures of at least 1530 psig (10.55 
MPa). 

2) Nearly all thermal heating fluids are 
flammable. Leaks within a fired heater 
can result in destruction of the heater. 
Leaks in external piping can result in 
fire and may result in an explosion. Wa- 
ter accumulation in a thermal heating 
system may cause upsets and possible 
fluid release from the system if the water 
contacts heated fluid (remember, flash- 



es 



NATIDNAL BOARD INSPECTION CODE • PART 2 



INSPECTION 



ing water expands approximately 1 600 
times.) It is essential for safe system 
operation to have installed and to main- 
tain appropriate fluid level, temperature 
and flow controls for liquid systems, 
and level, temperature and pressure 
controls for vapor systems. Expansion 
tanks used in thermal heater systems, 
including vented systems, should be 
designed and constructed to a recog- 
nized standard such as ASME Section 
VIII, Div. 1 , to withstand pressure surges 
that may occur during process upsets. 
This is due to the rapid expansion of 
water exceeding the venting capabil- 
ity. 

3) Because heat transfer fluids contract 
and become more viscous when 
cooled, proper controls and expansion 
tank venting are required to prevent 
low fluid level and collapse of the 
tank. Some commonly used fluids will 
solidify as high as 54°F (12°C). Others 
do not become solid until -40°F (-40°C) 
or even lower. The fluids that become 
viscous will also become difficult to 
pump when cooled. Increased viscos- 
ity could cause low flow rates through 
the heater. The heater manufacturer 
recommendations and the fluid man- 
ufacturer's Material Safety Data Sheets 
(MSDS) should be reviewed for heat 
tracing requirements. 

b) Industrial Applications 

Thermal fluid heaters, often called boilers, 
are used in a variety of industrial applica- 
tions such as solid wood products manufac- 
turing resins, turpentines, and various types 
of chemicals, drugs, plastics, corrugating 
plants, and wherever high temperatures are 
required. They are also frequently found 
in asphalt plants for heating of oils, tars, 
asphalt pitches, and other viscous materi- 
als. Many chemical plants use this type of 
heater in jacketed reactors or other types 
of heat exchangers. 



c) Inspection 

1) Inspection of thermal fluid heaters 
typically is done in either the operating 
mode or the shutdown mode. Internal 
inspections, however, are rarely pos- 
sible due to the characteristics of the 
fluids and the need to drain and store 
the fluid. Reliable and safe operation 
of a heater requires frequent analysis of 
the fluid to determine that its condition 
is satisfactory for continued operation. 
If the fluid begins to breakdown, carbon 
will form and collect on heat transfer 
surfaces within the heater. Overheat- 
ing and pressure boundary failure may 
result. Review of fluid test results and 
control and safety device maintenance 
records are essential in determining 
satisfactory conditions for continued 
safe heater operation. 

2) Due to the unique design and material 
considerations of thermal fluid heat- 
ers and vaporizers, common areas of 
inspection are: 

a. Design — specific requirements 
outlined in construction codes must 
be met. Some Jurisdictions may re- 
quire ASME Section I or Section VIII 
construction. Code requirements 
for the particular Jurisdiction should 
be reviewed for specific design 
criteria. 

b. Materials — for some thermal flu- 
ids, the use of aluminum or zinc 
anywhere in the system is not advis- 
able. Aluminum acts as a catalyst 
that will hasten decomposition of 
the fluid. In addition, some fluids 
when hot will cause aluminum 
to corrode rapidly or will dissolve 
zinc. The zinc will then form a 
precipitate that can cause localized 
corrosion or plug instrumentation, 
valves, or even piping in extreme 
cases. These fluids should not be 



29 



NATIONAL BOARD INSPECTION CODE • PART Z 



INSPECTION 



used in systems containing alumi- 
num or galvanized pipe. The fluid 
specifications will list such restric- 
tions. 

Note: Some manufacturers of these 
fluids recommend not using alumi- 
num paint on valves or fittings in 
the heat transfer system. 

c. Corrosion — when used in ap- 
plications and installations recom- 
mended by fluid manufacturer, 
heat transfer fluids are typically 
noncorrosive. However, some flu- 
ids, if used at temperatures above 
1 50°F (65°C) in systems containing 
aluminum or zinc can cause rapid 
corrosion. 

d. Leakage — any sign of leakage 
could signify problems since the 
fluid or its vapors can be hazard- 
ous as well as flammable. Areas 
for potential leaks include cracks 
at weld attachment points and tube 
thinning in areas where tubes are 
near soot blowers. The thermal fluid 
manufacturer specifications will list 
the potential hazards. 

e. Solidification of the Fluid — deter- 
mine that no conditions exist that- 
would allow solidification of the 
thermal fluid. When heat tracing or 
insulation on piping is recommend- 
ed by the heater manufacturer, the 
heat tracing and insulation should 
be checked for proper operation 
and installation. 

f. Pressure Relief Devices — all pres- 
sure relief devices should be con- 
nected to a closed, vented storage 
tank or blowdown tank and must 
be the type with a closed-bonnet, 
no manual lift lever, and solid piped 
discharge to an appropriately vent- 
ed receiver. If outdoor discharge 



is used, the following should be 
considered for discharge piping at 
the point of discharge: 

1 . Both thermal and chemical 
reactions (personnel hazard) 

2. Combustible materials (fire 
hazard) 

3. Surface drains (pollution and 
fire hazard) 

4. Loop seal or rain cap on the 
discharge (keep both air and 
water out of the system) 

5. Drip leg near device (prevent 
liquid collection) 

6. Heat tracing for systems using 
high freeze point fluids (pre- 
vent blockage) 



2.2.12.4 WASTE HEAT BOILERS 

a) Waste heat boilers are usually of firetube or 
watertube type and obtain their heat from 
an external source or process in which a 
portion of the BTUs have been utilized. 
Generation of electrical energy is usually 
the primary application of waste heat boil- 
ers. The biggest disadvantage of this type 
of boiler is that it is not fired on the basis 
of load demand. Since the boiler does not 
have effective control over the amount of 
heat entering the boiler, there may be wide 
variations or fluctuations of metal tempera- 
tures. Waste process gasses are usually in 
a temperature range of 400°F (205°C) to 
800°F (427°C), where combustion gasses 
of conventional-fired boilers are at about 
2000°F (1 093°C). Special design consider- 
ations are made to compensate for lower 
combustion gas temperatures such as the 
use of finned high-efficiency heat absorbing 
tubes, and by slowing the velocity of gasses 
through the boiler. 



3D 



NATIONAL BOARD INSPECTION CODE 8 PART Z INSPECTION 



b) Due to the unique design and material 
considerations of waste heat boilers, the fol- 
lowing are common areas of inspection: 

1) Corrosion — chemicals in waste heat 
gasses may create corrosive conditions 
and react adversely when combined 
with normal gasses of combustion. 
Water or steam leakage can create 
localized corrosion. Extreme thermal 
cycling can cause cracks and leakage 
at joints. 

2) Erosion — typically waste heat flow is 
very low and erosion is not a problem. 
However, when waste heat is supplied 
from an internal combustion engine, 
exhaust gasses can be high enough to 
cause erosion. 

3) Vibration — in some process applica- 
tions and all engine waste heat appli- 
cations, the boiler may be subjected to 
high vibration stresses. 

4) Acid Attack — in sulfuric acid processes 
refractory supports and steel casings are 
subject to acid attack. Piping, filters, 
heat exchangers, valves, fittings, and 
appurtenances are subject to corrosive 
attacks because these parts are not 
normally made of corrosion resistant 
materials. 

5) Dry Operation — in certain applica- 
tions waste heat boilers are operated 
without water. Care must be taken not 
to expose carbon steel material to tem- 
peratures in excess of 800° F (427°C) for 
prolonged periods. Carbides in the steel 
may precipitate to graphite at elevated 
temperatures. 



2.2.12.5 CAST-IRON BOILERS 

a) Cast-iron boilers are used in a variety of 
applications to produce low or high pres- 
sure steam and hot water heat. Cast-iron 
boilers should only be used in applica- 



tions that allow for nearly 100% return of 
condensate or water, and are not typically 
used in process-type service. These boilers 
are designed to operate with minimum 
scale, mud, or sludge, which could occur 
if makeup water is added to this system. 

b) Due to the unique design and material 
considerations of cast-iron boilers, the fol- 
lowing are common areas of inspection: 

1 ) Scale and Sludge — since combustion 
occurs at or near the bottom, accumu- 
lation of scale or sludge close to the 
intense heat can cause overheating and 
lead to cracking. 

2) Feedwater — makeup feedwater should 
not come in contact with hot surfaces. 
Supply should be connected to a return 
pipe for tempering. 

3) Section Alignment — misalignment of 
sections can cause leakage. Leakage or 
corrosion between sections will not al- 
low normal expansion and contraction 
that may cause cracking. 

4) Tie Rods or Draw Rods — used to as- 
semble the boiler and pull the sections 
together. These rods must not carry any 
stress and need to be loose, allowing 
for section growth during heat up. 
Expansion washers may be used and 
nuts should be just snugged allowing 
for expansion. 

5) Push Nipple or Seal Area — corrosion 
or leakage is likely at the push nipple 
opening, usually caused by the push 
nipple being pushed into the seat 
crooked, warping due to overheating, 
tie rods too tight, and push nipple cor- 
rosion/erosion. 

6) Corrosion — firesides of sections 
can corrode due to ambient moisture 
coupled with acidic flue gas deposits. 



3 i 



NATIONAL BOARD INSPECTION CODE • PART Z 



INSPECTION 



7) Soot — inadequate oxygen supply or 
improperly adjusted burner can allow 
for soot buildup in fireside passages. A 
reduction in efficiency and hot spots 
may occur. Soot, when mixed with wa- 
ter, can form acidic solutions harmful 
to the metal. 



and may be used in conjunction with a 
hot-water storage vessel. 

b) Due to the unique design and material 
considerations of fired coil water heaters, 
the following are common areas of inspec- 
tion: 



2.2.12.6 ELECTRIC BOILERS 

a) Electric boilers are heated by an electrical 
energy source, either by use of electric re- 
sistant coils or induction coils. These boilers 
may be used in either high or low pressure 
steam or hot water applications. 

b) Due to the unique design and material con- 
siderations of electric boilers, the following 
are common areas of inspection: 

1 ) Weight Stress of the Elements — some 
electrodes and elements can be quite 
heavy, especially if covered with scale 
deposits. These elements will scale 
sooner and at a faster rate than internal 
surfaces. Excessive weight puts severe 
stress on the attachment fittings and 
welds at support points. 

2) Thermal Shock — heaters are constantly 
cycling on and off creating temperature 
gradients, but are less susceptible to 
thermal shock than a fired boiler. 

3) Leakage — any leakage noted at the 
opening where electrodes or elements 
are inserted is extremely dangerous due 
to the possible exposure of electrical 
wires, contacts, and breakers. 



2.2.12.7 FIRED COIL WATER HEATERS 

a) Fired coil water heaters are used for rapid 
heating of potable water or hot water ser- 
vice. This design utilizes a coil through 
which the water being heated is passed. 
This type of heater has very little volume 



1) Erosion — size and velocity of water 
flow through the coil combines to 
create wear and thinning of the coils. 
If a temperature differential is created 
within the coil, bubbles or steam may 
cause grooving or cavitation. 

2) Corrosion — this type of system uses 
100% makeup water that contains 
free oxygen creating opportunities for 
extensive corrosion. 

3) Vibration — operation of the burner 
creates a certain amount of vibration. 
Creation of steam, hot spots, or lack of 
flow may create a water hammer caus- 
ing extensive vibration and mechanical 
stresses. 

4) Scale — due to the large volume of 
makeup, significant amounts of scale 
forming particles will adhere to the hot 
surfaces. 



2.2.12.8 F!RED STORAGE WATER 
HEATERS 

a) Fired storage water heaters are vertical 
pressure vessels containing water to which 
heat is applied. Typically gas burners are 
located directly beneath the storage vessel. 
These heaters should be insulated and fitted 
with an outer jacket and may be lined with 
porcelain, glass, galvanized metal, cement, 
or epoxy. 

b) Due to the unique design and material 
considerations of fired storage water heat- 
ers, the following are common areas of 
inspection: 



32 



NATIONAL BOARD INSPECTION CODE - PART 2 — INSPECTION 



1 ) Corrosion — moisture may be trapped 
between the insulation and outer 
jacket, which may cause corrosion of 
the pressure boundary. 

2) Mud and Sludge — there is 100% 
makeup of water allowing for accumu- 
lation of mud and sludge in the bottom 
portions of the vessel. Any buildup can 
cause overheating and failure of the 
metal in this area. 

3) Scale — loose scale may accumulate in 
areas adjacent to the burner and lower 
portions of the vessel, interfering with 
heat transfer process and causing local- 
ized overheating. Scale and sludge can 
also shield temperature control probes 
giving false readings and allowing the 
water to overheat. 

4) Thermal Cycling — heated water is con- 
tinually replaced with cold water caus- 
ing thermal stress within the vessel. 

5) Lining — loss of lining or coating will 
allow for rapid deterioration of the pres- 
sure boundary. 

6) Pressure — if water supply pressure 
exceeds 75% of set pressure of safety 
relief valve, a pressure reducing valve 
may be required. 

7) Expansion — if the water heater can 
be isolated by devices such as a check 
valve, it is recommended that an expan- 
sion tank be provided. 



2.2.12.9 FIRETUBE BOILERS 

a) The distinguishing characteristic of a fire- 
tube boiler is that the products of combus- 
tion pass within tubes that are surrounded 
by the water that is being heated. Combus- 
tion of fuel takes place within the furnace 
area with the resultant products of combus- 
tion traveling through one or more groups 



of tubes before exiting the boiler. Firetube 
boilers are classified by the arrangement of 
the furnace and tubes such as Horizontal 
Return Tubular (HRT) boiler, Firetube Fire 
Box (FTFB) boiler, or Vertical Tubular (VT) 
boiler. The number of passes that the prod- 
ucts of combustion make through the tubes 
is also used in classifying the type of boiler, 
such as a two-pass or three-pass boiler. 

b) Firetube boilers may be used in hot water 
or steam applications. They may be either 
low pressure or high pressure construction, 
but typically are not designed for pressures 
greater than 250 psig. Steam capacities are 
generally less than 30,000 Ib/hr. Firetube 
boilers are found in a wide variety of ap- 
plications ranging from heating to process 
steam to small power generation. 

c) Firetube boilers are subject to thermal 
stresses due to cycling, which may cause 
tube leakage and corrosion of joints. The 
following items are common areas of in- 
spection: 

1) Waterside — scale buildup on and 
around the furnace tube. Scale on or 
around the firetubes in the first pass 
after the furnace (gas temperatures 
>1 800°F [980°C]). Scale and corrosion 
buildup on stay rods hiding the actual 
diameter. Corrosion pitting on all pres- 
sure boundaries. 

2) Fireside — Tube to tube sheet joint leak- 
age. Look for rust trails left by weeping 
joints. When in doubt where the leak- 
age is coming from, perform a liquid 
penetrant exam. Take note of refractory 
locations protecting steel that is not 
water cooled. Partial or complete re- 
moval of the refractory may be required 
for inspection purposes. Condensation 
of combustion gas dripping out of the 
fireside gaskets during a cold boiler start 
up is expected. However, if it continues 
after the water temperature in the boiler 
is at least 1 50°F (65°C), then further 



33 



NATIONAL BOARD INSPECTION CODE • PART Z 



INSPECTION 



investigation to determine the source 
of water shall be conducted. 

d) Practical considerations lead to the use 
of basically cylindrical shells. Flat-end 
tubesheet surfaces are supported by various 
methods: diagonal stays, through-bolts, or 
the tubes themselves. Tubes may be rolled, 
welded, or rolled and seal-welded into the 
tubesheets. For steam applications, the wa- 
ter level is maintained several inches above 
the uppermost row of tubes, which allows 
for a steam space in the upper portion of 
the boiler shell. There are several different 
types of firetube boilers: 

1 ) Firetube Scotch Marine (FTSM) 

a. A Firetube Scotch Marine boiler 
consists of a horizontal cylindrical 
shell with an internal furnace. Fuel 
is burned in the furnace with the 
products of combustion making 
two, three, or four passes through 
the boiler tubes. The rear door may 
be either a dry refractory lined de- 
sign (dry back), or a water-cooled 
(wet back) design. Two designs of 
the furnace are commonly used: 
one, the corrugated type, is known 
as a Morrison furnace; the other is 
the plain furnace. 

b. The FTSM boiler design is one of 
the oldest firetube boiler designs 
with internal furnaces. Extensive 
use in early marine service added 
"marine" to the name of this type of 
boiler. Currently both the wet back 
design and the dry back design can 
be found in stationary applications. 
Firetube Scotch marine boilers are 
used for both high pressure and low 
pressure steam applications and are 
also used for hot water service. 



2) Horizontal Return Tubular (HRT) 

a. A Horizontal Return Tubular boiler 
consists of a cylindrical shell with 
flat tube sheets on the ends. The 
tubes occupy the lower two thirds 
of the shell with a steam space 
above the tubes. The shell is sup- 
ported by brick work under the 
boiler. The external furnace box is 
in front of the shell support brick- 
work and is below the front tube 
sheet. The furnace box is typically 
quite large primarily to support the 
combustion of solid fuel. HRT boil- 
ers were quite common in the early 
to mid 1 900s. The design is quite in- 
efficient due to the one pass design 
and the large amount of brickwork 
that is heated by the products of 
combustion. One particular area 
of concern for this type of boiler is 
the bottom blowdown line, which 
passes through the rear part of the 
furnace box and is directly exposed 
to the products of combustion. 
A refractory baffle must properly 
protect the bottom blowdown line. 
Another specific area of concern 
is the shell supporting brick work. 
Over time, the brick work may have 
deteriorated and can no longer pro- 
vide adequate support for the boiler 
shell. These boilers are frequently of 
riveted construction. 

b. HRT boilers were originally used 
for both high pressure and low 
pressure steam applications. Units 
that are still in service are typically 
found in old industrial facilities and 
are generally only used for steam 
heating applications. 

3) Firetube Fire Box (FTFB) 

a. FireTube Fire Box boilers were 
popular in the mid-1 900s, although 
many can still be found in service. 



34 



NATIONAL BOARD INSPECTION CODE • PART 2 



INSPECTION 



An FTFB boiler consists of an ex- 2.3 
ternal furnace that is enclosed by 
water legs on three or four sides. 
The water legs extend upward to 2.3.1 
the crownsheet to form the lower 
part of the boiler shell while the 
upper part of the shell is formed by 
the extension of the water leg outer 
shell. Flat heads are used on both 
ends of the boiler shell. The boilers 
may be two-, three-, or four-pass 
designs. 

b. Since the water legs of FTFB boilers 2.3.2 
are the lowest point of the water 
side, loose scale and sludge tends a) 
to accumulate. Besides interfering 
with water flow, the accumulated 
sediment may accelerate corrosion 
of water leg stay bolts or the water 
legs themselves. The hand holes in 
the water legs should be open dur- 
ing an internal inspection. 

4) Locomotive 
Locomotive boilers are similar in design 
to the boi lers on old steam locomotives. 
This design saw limited stationary ap- 
plications and few remain in service 
today. Most are of riveted construction. 
See Supplement 1 for detailed draw- 
ings. 

5) Vertical Firetube 

As the name implies, vertical firetube 
boilers are arranged with the shell and b) 
tubes in the vertical orientation. These 
boilers are generally small, (<1 0,000 
Ib/hr [< 4, 535.92 kg/hr] capacity) and 
are used where the rapid development 
of steam is necessary for operation. Ver- 
tical firetube boilers are found in many 
high- and low-pressure applications. 
The burner may be located on top or 
bottom of the boiler. Due to their small 
size and frequent application where 
considerable makeup water is used, 
scale development is an important 
concern. 



PRESSURE VESSELS 



SCOPE 



This section provides guidelines for inservice 
inspection of pressure vessels used to contain 
pressure either internal or external. This pres- 
sure may be obtained from an external source 
or by the application of heat from a direct or 
indirect source or a combination thereof. 



SERVICE CONDITIONS 



Pressure vessels are designed for a variety 
of service conditions. The media that a pres- 
sure vessel contains and the temperature 
and pressure at which it operates should 
be considered in establishing inspection 
criteria. Usage, materials, and installa- 
tion conditions should be considered in 
determining damage mechanisms that 
will affect the mechanical integrity of a 
pressure vessel as described in Section 3 
of this Part. The general requirements for 
safety, pre-inspection, and post-inspection 
activities are specified in Section 1 of this 
Part and should be followed in conjunction 
with the specific requirements outlined in 
this section when performing inspections of 
pressure vessels. There may be occasions 
where more detailed procedures will be 
required. 

The type of inspection given to pressure 
vessels should take into consideration the 
condition of the vessel and the environ- 
ment in which it operates. This inspection 
may be either external or internal and use 
a variety of nondestructive examination 
methods as described in Section 4 of this 
Part. The inspection method may be per- 
formed when the vessel is operating on- 
stream or depressurized, but shall provide 
the necessary information to determine 
that the essential sections of the vessel are 
in satisfactory condition to operate for the 
expected time interval. On-stream inspec- 



35 



NATIONAL BOARD INSPECTION CODE • PART Z 



INSPECTION 



tion, including while under pressure, may 
be used to satisfy inspection requirements 
provided the accuracy of the method can 
be demonstrated. 

New pressure vessels are placed in service 
to operate under their design conditions for 
a period of time determined by the service 
conditions and the corrosion rate. If the 
pressure vessel is to remain in operation, 
the allowable conditions of service and the 
length of time before the next inspection 
shall be based on the conditions of the 
vessel as determined by the inspection. See 
5.3 for determining remaining service life 
and inspection intervals. 



2.3.3 



EXTERNAL INSPECTION 



The purpose of an external inspection is to 
provide information regarding the general 
condition of the pressure vessel. The following 
should be reviewed: 



c) Structural Attachments 

The pressure vessel mountings should be 
checked for adequate al lowance for expan- 
sion and contraction, such as provided by 
slotted bolt holes or unobstructed saddle 
mountings. Attachments of legs, saddles, 
skirts, or other supports should be exam- 
ined for distortion or cracks at welds. 

d) Vessel Connections 

Manholes, reinforcing plates, nozzles, or 
other connections should be examined for 
cracks, deformation, or other defects. Bolts 
and nuts should be checked for corrosion 
or defects. Weep holes in reinforcing plates 
should remain open to provide visual evi- 
dence of leakage as wel I as to prevent pres- 
sure buildup between the vessel and the 
reinforcing plate. Accessible flange faces 
should be examined for distortion and to 
determine the condition of gasket-seating 
surfaces. 

e) Miscellaneous Conditions 



a) Insulation or Other Coverings 

If it is found that external coverings such as 
insulation and corrosion-resistant linings 
are in good condition and there is no rea- 
son to suspect any unsafe condition behind 
them, it is not necessary to remove them for 
inspection of the vessel. However, it may 
be advisable to remove small portions of 
the coverings in order to investigate attach- 
ments, nozzles, and material conditions. 

Note: Precautions should be taken when 
removing insulation while vessel is under 
pressure. 

b) Evidence of Leakage 

Any leakage of gas, vapor, or liquid should 
be investigated. Leakage coming from 
behind insulation coverings, supports or 
settings, or evidence of past leakage should 
be thoroughly investigated by removing 
any covering necessary until the source of 
leakage is established. 



1 ) Abrasives — The surfaces of the vessel 
should be checked for erosion. 

2) Dents — Dents in a vessel are deforma- 
tions caused by their coming in contact 
with a blunt object in such a way that 
the thickness of metal is not materially 
impaired. Dents can create stress risers 
that may lead to cracking. 

3) Distortion — If any distortion is sus- 
pected or observed, the overall dimen- 
sions of the vessel shall be checked to 
determine the extent and seriousness 
of the distortion. 

4) Cuts or Gouges — Cuts or gouges can 
cause high stress concentrations and 
decrease the wall thickness. Depending 
upon the extent of the defect, it may be 
necessary to repair. 

5) Surface Inspection — The surfaces of 
shells and heads should be examined 



36 



NATIONAL BOARD INSPECTION CODE • PART 2 



INSPECTION 



for possible cracks, blisters, bulges, cor- 
rosion, erosion, and other evidence of 
deterioration, giving particular attention 
to the skirt and to support attachment 
and knuckle regions of the heads. 

6) Weld Joints — Welded joints and the 
adjacent heat affected zones should be 
examined for cracks or other defects. 
Magnetic particle or liquid penetrant 
examination is a useful means for doing 
this. 

7) Riveted Vessels — On riveted vessels, 
examine rivet head, butt strap, plate, 
and caulked edge conditions. If rivet 
shank corrosion is suspected, hammer 
testing for soundness or spot radiogra- 
phy at an angle to the shank axis may 
be useful. 



2.3.4 INTERNAL INSPECTION 

a) A general visual inspection is the first step 
in making an internal inspection of pressure 
vessels that are susceptible to corrosion. 
Vessels should be inspected for the condi- 
tions identified in Section 3 of this Part. 

b) The following should be reviewed: 

1) Vessel Connections 

Threaded connections should be in- 
spected to ensure that an adequate 
number of threads are engaged. All 
openings leading to any external fit- 
tings or controls should be examined 
as thoroughly as possible to ensure they 
are free from obstructions. 

2) Vessel Closures 

Any special closures including those 
on autoclaves, normally termed quick 
actuating (quick opening) closures, see 
2.3.6.5, that are used frequently in the 
operation of a pressure vessel, should 
be checked by the Inspector for integrity 
and wear. A check should also be made 



for cracks at areas of high stress concen- 
tration. Door safety interlock mecha- 
nisms, "man inside" alarm and associ- 
ated audible and visual alarms should 
be verified. The man inside alarm, is a 
safety cable running the length of the 
internal workspace that can be pulled 
by the operator, thereby shutting down 
all autoclave functions and initiating 
audible and visual alarms. 

3) Vessel Internals 

a. Where pressure vessels are equipped 
with removable internals, these 
internals need not be completely 
removed provided assurance exists 
that deterioration in regions ren- 
dered inaccessible by the internals 
is not occurring to an extent that 
might constitute a hazard, or to an 
extent beyond that found in more 
readily accessible parts of the ves- 
sel. 

b. If a preliminary inspection reveals 
unsafe conditions such as loose or 
corroded internals or badly cor- 
roded internal ladders or platforms, 
steps should be taken to remove or 
repair such parts so that a detailed 
inspection may be made. 

4) Corrosion 

The type of corrosion (local pitting or 
uniform), its location, and any obvious 
data should be established. Data col- 
lected for vessels in similar service will 
aid in locating and analyzing corrosion 
in the vessel being inspected. The liquid 
level lines, the bottom, and the shell 
area adjacent to and opposite inlet 
nozzles are often locations of most se- 
vere corrosion. Welded seams, nozzles, 
and areas adjacent to welds are often 
subjected to accelerated corrosion. 



37 



NATIONAL BOARD INSPECTION CODE • PART 2 



INSPECTION 



2.3.5 INSPECTION OF PRESSURE 

VESSEL PARTS AND 
APPURTENANCES 

Parts and appurtenances to be inspected de- 
pend upon the type of vessel and its operating 
conditions. The Inspector should be familiar 
with the operating conditions of the vessel and 
with the causes and characteristics of potential 
defects and deterioration. 



2.3.5.1 



GAGES 



a) The pressure indicated by the required gage 
should be compared with other gages on 
the same system. If the pressure gage is 
not mounted on the vessel itself, it shall be 
installed in such a manner that it correctly 
indicates the actual pressure in the vessel. 
When required, the accuracy of pressure 
gages should be verified by comparing the 
readings with a calibrated test gage or a 
dead weight tester. 

b) The location of a pressure gage should be 
observed to determine whether it is exposed 
to high temperature from an external source 
or to internal heat due to lack of protec- 
tion by a proper siphon or trap. Provisions 
should be made for blowing out the pipe 
leading to the steam gage 



2.3.5.2 SAFETY DEVICES 

See 2.5 for the inspection of safety devices 
(pressure relief valves and non-closing devices 
such as rupture disks) used to prevent the over- 
pressure of pressure vessels. 



2.3.5.3 CONTROLS/DEVICES 

a) Any control device attached to a vessel 
should be demonstrated by operation or the 
Inspector should review the procedures and 
records for verification of proper operation. 



b) Temperature measuring devices shall be 
checked for accuracy and general condi- 
tion. 



2.3.5.4 RECORDS REVIEW 

a) The Inspector shall review any pressure 
vessel log, record of maintenance, corro- 
sion rate record, or any other examination 
results. The Inspector should consult with 
the owner or user regarding repairs or al- 
terations made, if any, since the last inter- 
nal inspection. The Inspector shall review 
the records of such repairs or alterations 
for compliance with applicable require- 
ments. 

b) A permanent record shall be maintained 
for each pressure vessel. This record should 
include the following: 

1) An ASME Manufacturer's Data Report 
or, if the vessel is not ASME Code 
stamped, other equivalent specifica- 
tions or reports. 

2) Form NB-5, Boiler or Pressure Vessel 
Data Report — First Internal Inspec- 
tion, may be used for this purpose. It 
shall show the following identification 
numbers as applicable: 

a. National Board No. 

b. Jurisdiction No. 

c. Manufacturer Serial No. 

d. Owner-User No. 

3) Complete pressure-relieving device 
information including safety or safety 
relief valve spring data, or rupture disk 
data and date of latest inspection. 

4) Progressive record including, but not 
limited to, the following: 



38 



NATIONAL BOARD INSPECTION CODE • PART 2 — INSPECTION 



a. Location and thickness of monitor 
samples and other critical inspec- 
tion locations. 

b. Limiting metal temperature and 
location on the vessel when this is a 
factor in establishing the minimum 
allowable thickness. 

c. Computed required metal thick- 
nesses and maximum allowable 
working pressure for the design 
temperature and pressure-reliev- 
ing device opening pressure, static 
head, and other loadings. 

d. Test pressure, if tested at the time 
of inspection. 

e. Required date of next inspection. 

5) Date of installation and date of any 
significant change in service conditions 
(pressure, temperature, character of 
contents, or rate of corrosion). 

6) Drawings showing sufficient details to 
permit calculation of the service rating 
of all components on pressure vessels 
used in process operations subject to 
corrosive conditions. Detailed data 
with sketches, where necessary, may 
serve this purpose when drawings are 
not available. 



2.3.6 DESCRIPTION AND CONCERNS 

OF SPECIFIC TYPES OF 
PRESSURE VESSELS 

Inspection and examination requirements iden- 
tified below should also include any additional 
requirements mentioned above. 



2.3.6.1 



DEAERATORS 



a) A deaerator is used to remove undesirable 
gases and is exposed to the following ser- 



vice conditions: harmful gases, fluctuation 
in temperature and pressure, erosion, and 
vibration. The air and water atmosphere in 
the deaerator has a corrosive effect and may 
contain high concentrations of hydrogen 
ions, which can cause hydrogen crack- 
ing, hydrogen embrittlement, or corrosion 
fatigue. The water entering the deaerator 
sometimes carries acids or oil that can 
cause acidic attacks on the metal. 

b) Inspection shall consist of the following: 

1) Welds — Inspect all longitudinal and 
circumferential welds, including the 
Heat Affected Zone (HAZ), visually 
along their entire length. Examine noz- 
zle and attachment welds for erosion, 
corrosion, or cracking. Inspect with 
special attention all exposed internal 
welds at or below the normal water 
line. 

2) Shell — Inspect exterior surfaces for 
corrosion or leaks. Inspect interior for 
pitting, corrosion, erosion, thinning, 
wastage of metal, cracks, etc. 

3) Spray Nozzles and Trays — Inspect all 
nozzles and spray areas for erosion, 
wear, wastage, and broken parts or 
supports. Check to see that nozzles are 
not plugged and that all lines to nozzles 
are open. Inspect all trays for holes, 
erosion, wastage, broken or defective 
brackets, and broken support attach- 
ments. 

4) Condenser and Vents — Examine all 
vent lines to see that they are open 
to assure proper exiting of the gases. 
Inspect the condenser unit to verify it 
is operable and not plugged with scale 
or sludge. Check for corrosion, pitting, 
erosion, and broken parts. 

5) Supports — Inspect all support struc- 
tures for mechanical damage, cracks, 
loose bolting, and bent or warped 



39 



NATIONAL BOARD INSPECTION CODE • PART 2 — INSPECTION 



components. Check all welds, espe- 
cially attaching supports to the pressure 
boundary. 



2.3.6.2 COMPRESSED AIR VESSELS 

a) Compressed air vessels include receivers, 
separators, filters, and coolers. Consider- 
ations of concern include temperature vari- 
ances, pressure limitations, vibration, and 
condensation. Drain connections should be 
verified to be free of any foreign material 
that may cause plugging. 

b) Inspection shall consist of the following: 

1) Welds — Inspect all welds for cracking 
or gouging, corrosion and erosion. Par- 
ticular attention should be given to the 
welds that attach brackets supporting 
the compressor. These welds may fail 
due to vibration. 

2) Shells/Heads — Externally, inspect the 
base material for environmental dete- 
rioration and impacts from objects. Hot 
spots and bulges are signs of overheat- 
ing and should be noted and evaluated 
for acceptability. Particular attention 
should be paid to the lower half of the 
vessel for corrosion and leakage. For 
vessels with manways or inspection 
openings, an internal inspection should 
be performed for corrosion, erosion, 
pitting, excessive deposit buildup, and 
leakage around inspection openings. 
UT thickness testing may be used where 
internal inspection access is limited or 
to determine actual thickness when 
corrosion is suspected. 

3) Fittings and Attachments — Inspect all 
fittings and attachments for alignment, 
support, deterioration, damage, and 
leakage around threaded joints. Any 
internal attachments such as supports, 
brackets, or rings shall be visually ex- 
amined for wear, corrosion, erosion, 
and cracks. 



4) Operation — Check the vessel name- 
plate to determine the allowed working 
pressure and temperature of the vessel. 
Assure the set pressure of the safety 
valve does not exceed that allowed on 
the vessel nameplate and determine 
that the capacity of the safety valve is 
greater than the capacity of the com- 
pressor. Ensure there is a functioning 
manual or automatic condensate 
drain. 

5) Quick-Closure Attachments — Filter- 
type vessels usually have one quick- 
type closure head for making filter 
changes see 2.3.6.5. 



2.3.6.3 



EXPANSION TANKS 



a) The purpose of an expansion tank is to 
provide an air cushion to a system that will 
allow for expansion and contraction, thus 
minimizing fluctuations in pressure due to 
temperature variances. These vessels are 
susceptible to corrosion due to the air and 
water interface. 

b) Inspection shall consist of the following; 

1) Design/Operation — Verify from the 
nameplate the code of construction, 
temperature, and pressure ratings to as- 
sure jurisdictional and system compat- 
ibility. It is common to find expansion 
tanks water logged due to leakage of air 
out of the tank, therefore it is important 
to verify the water level either by sight 
glass or sounding the tank. If the vessel 
is fitted with a water sight glass, inspect 
for visual cleanliness, water leakage, 
and gasket tightness. 

2) Surface Conditions — Check all surfac- 
es external and internal, if possible, for 
any leaks, corrosion, erosion, cracks, 
and dents that may lead to failure. 
Thickness checks may be applicable to 
determine any reduction of base mate- 
rial thickness. 



4D 



NATIONAL BOARD INSPECTION CODE • PART 2 — INSPECTION 



3) Supports and Attachments — These 
vessels are usually suspended from the 
ceiling by hangers or straps causing 
concentration of stresses in these areas. 
Specifically inspect for corrosion, wear, 
and cracks in these areas. 



2.3.6.4 LIQUID AMMONIA VESSELS 

Vessels in liquid ammonia service are suscep- 
tible to stress corrosion cracking (SCC) (see 
3.3.2 [b]) in areas of high stress. High strength 
and coarse-grained materials seem to be more 
at risk of SCC than are fine-grained or more 
moderate strength materials, although no 
commonly used steels appear to be immune 
to the problem. Postweld heat treatment of 
new or weld-repaired vessels or cold formed 
heads is beneficial in reducing the incidence 
of SCC. The presence of 0.2% minimum water 
in the liquid ammonia also inhibits SCC. Any 
leak should be thoroughly investigated and the 
necessary corrective action initiated. 

a) Inspection of Parts and Appurtenances 

1) Where existing openings permit, per- 
form a visual internal inspection of the 
vessel. Look for any obvious cracks 
(very advanced SCC) and note areas 
that are subject to high stress such as 
welds, welded repairs, head-to-shell 
transitions, sharp interior corners, and 
interior surfaces opposite external at- 
tachments or supports. Alternatively, an 
internal inspection may be conducted 
from the outside utilizing suitable NDE, 
e.g., ultrasonic techniques. 

2) If valves or fittings are in place, check 
to ensure that these are complete and 
functional. Parts made of copper, zinc, 
silver, or alloys of these metals are 
unsuitable for ammonia service and 
should be replaced with parts fabricat- 
ed of steel or other suitable materials. 



3) Fittings should be removed or other- 
wise protected from power buffing or 
light sandblasting when preparing the 
interior surface of the vessels for inspec- 
tion. 

4) All interior welds and highly stressed 
areas should be examined by the wet 
fluorescent magnetic particle-testing 
method (VVFMT) using an A/C yoke for 
magnetization. Note that weld cracks 
are often transverse in orientation. It is 
extremely important to ensure that the 
NDE method used will disclose cracks 
in any orientation. 

5) If cracks are discovered, a calculation 
must be made to determine what depth 
of grinding may be carried out for crack 
removal (without encroaching on the 
minimum thickness required by the 
construction standard or equivalent). 

6) Where possible, crack removal by 
grinding is the preferred method of re- 
pair. Since the stresses at the crack tips 
are quite high, even very fine cracking 
should be eliminated. 

7) Where crack depth is such that removal 
requires weld repair, a weld procedure 
should be employed that will minimize 
HAZ hardening and residual stresses. 
Whenever possible, weld repairs re- 
gardless of their size should be post- 
weld heat treated. 

8) Re-inspect by WFMT to ensure com- 
plete crack removal. 

9) It is not intended to inhibit or limit the 
use of other evaluation methods. It is 
recognized that acoustic emission and 
fracture mechanics are acceptable tech- 
niques for assessing structural integrity 
of vessels. Analysis by fracture mechan- 
ics may be used to assess the structural 
integrity of vessels when complete re- 



4 1 



NATIONAL BOARD INSPECTION CODE • PART Z 



INSPECTION 



moval of all ammonia stress cracks is 
not practical. If alternative methods are 
used, the above recommendation that 
all cracks be removed, even fine cracks 
may not apply. 

b) Inspection of Insulated Vessels 

1) Insulated pressure vessels can suffer 
from aggressive external corrosion that 
is often found beneath moist insulation. 
The Inspector should closely examine 
the external insulation scaling surfaces 
for cold spots, bulges, rust stains, or any 
unusual conditions in previous repair 
areas. Bulging or distorted insulation 
on refrigerated vessels may indicate 
the formation of ice patches between 
the vessel shell and insulation due to 
trapped moisture. Careful observation 
is also required where the temperature 
of insulated vessels cycle continu- 
ally through the freezing temperature 
range. 

2) The lower 1/3 to 1/2 and the bottom 
portions of insulated vessels should re- 
ceive special focus, as condensation or 
moisture may gravitate down the vessel 
shell and soak into the insulation keep- 
ing it moist for long periods of time. 
Penetration locations in the insulation 
such as saddle supports, nozzles, or 
fittings should be examined closely for 
potential moisture ingress paths. When 
moisture penetrates the insulation, the 
insulation may actually work in reverse 
holding moisture in the insulation and/ 
or near the vessel shell. 

3) Insulated vessels that are run on an 
intermittent basis, or that have been 
out of service require close scrutiny. 
In general, a visual inspection of the 
external surfaces of insulated vessels 
should be conducted once per year. 

4) The most common and superior method 
to inspect for suspected corrosion un- 



der insulation damage (CUI) is to com- 
pletely or partially remove the insula- 
tion for visual inspection. The method 
most commonly utilized to inspect for 
CUI without insulation removal is by 
x-ray and isotope radiography (film 
or digital) or by real time radiography 
utilizing imaging scopes and surface 
profilers. The real time imaging tools 
will work well if the vessel geometry 
and insulation thickness allows. Other 
less common methods to detect CUI 
include specialized electromagnetic 
methods (pulsed eddy current and 
electromagnetic waves), and long range 
ultrasonic techniques (guided waves). 

5) There are also several methods to detect 
moisture soaked insulation, which is 
often the beginning for potential CUI 
damage. Moisture probe detectors, 
neutron backscatter, and thermogra- 
phy are tools that can be used for CUI 
moisture screening. 

6) Proper surface treatment (coating) of the 
vessel external shell and maintaining 
weather tight external insulation are the 
keys to prevention of CUI damage. 

c) Gages and Pressure-Relieving Devices 

1 ) The Inspector should note the pressure 
indicated by the gage and compare it 
with other gages on the same system. 
If the pressure gage is not mounted on 
the vessel itself, it should be ascertained 
that the gage is installed on the system 
in such a manner that it correctly indi- 
cates actual pressure in the vessel. 

2) See 2.5 for the inspection of safety relief 
devices (pressure relief valves) used to 
prevent the overpressure of liquid am- 
monia vessels. Pressure-relief devices 
in ammonia service shall not be tested 
in place using system pressure. Bench 
testing is required. 



42 



NATIONAL BOARD INSPECTION CODE • PART 2 



INSPECTION 



2.3.6.5 INSPECTION OF PRESSURE 
VESSELS WITH QUICK- 
ACTUATING CLOSURES 

a) This section describes guidelines for in- 
spection of pressure vessels equipped 
with quick-actuating closures. Due to the 
many different designs of quick-actuating 
closures, potential failures of components 
that are not specifically covered should be 
considered. The scope of inspection should 
include areas affected by abuse or lack of 
maintenance and a check for inoperable or 
bypassed safety and warning devices. 

b) Temperatures above that for which the 
quick-actuating closure was designed can 
have an adverse effect on the safe operation 
of the device. If parts are found damaged 
and excessive temperatures are suspected 
as the cause, the operating temperatures 
may have exceeded those temperatures 
recommended by the manufacturer. Rapid 
fluctuations in temperatures due to rapid 
start-up and shutdown may lead to cracks 
or yielding caused by excessive warping 
and high thermal stress. A careful observa- 
tion should be made of the condition of 
the complete installation, including main- 
tenance and operation, as a guide in form- 
ing an opinion of the care the equipment 
receives. The history of the vessel should be 
established, including: year built, materials 
of construction, extent of postweld heat 
treatment, previous inspection results, and 
repairs or alterations performed. Any leak 
should be thoroughly investigated and the 
necessary corrective action initiated. 

1 ) Inspection of Parts and Appurtenances 

a. Seating surfaces of the closure 
device, including but not limited 
to the gaskets, O-rings, or any me- 
chanical appurtenance to ensure 
proper alignment of the closure 
to the seating surface, should be 
inspected. This inspection can be 
made by using powdered chalk or 



any substance that will indicate that 
the closure is properly striking the 
seating surface of the vessel flange. 
If this method is used, a check 
should be made to ensure that: 

1 . Material used will not con- 
taminate the gasket or mate- 
rial with which it comes into 
contact. 

2. The substance used should be 
completely removed after the 
examination. 

b. The closure mechanism of the 
device should be inspected for 
freedom of movement and proper 
contact with the locking elements. 
This inspection should indicate 
that the movable portions of the 
locking mechanism are striking the 
locking element in such a manner 
that full stroke can be obtained. 
Inspection should be made to en- 
sure that the seating surface of the 
locking mechanism is free of metal 
burrs and deep scars, which would 
indicate misalignment or improper 
operation. A check should be made 
for proper alignment of the door 
hinge mechanisms to ensure that 
adjustment screws and locking 
nuts are properly secured. When 
deficiencies are noted, the follow- 
ing corrective actions should be 
initiated: 

1 . If any deterioration of the gas- 
ket, O-ring, etc., is found, the 
gasket, O-ring, etc., should 
be replaced immediately. 
Replacements should be in 
accordance with the vessel 
manufacturer's specifications. 

2. If any cracking or exces- 
sive wear is discovered on 
the closing mechanism, the 
owner or user should contact 



43 



NATIDNAL BOARD INSPECTION CODE • PART 2 



INSPECTION 



the original manufacturer 
of the device for spare parts 
or repair information. If this 
cannot be accomplished, the 
owner or user should contact 
an organization competent 
in quick-actuating closure 
design and construction prior 
to implementing any repairs. 

3. Defective safety or warning 
devices should be repaired 
or replaced prior to further 
operation of the vessel. 

4. Deflections, wear, or warping 
of the sealing surfaces may 
cause out-of-roundness and 
misalignment. The manufac- 
turer of the closure should 
be contacted for acceptable 
tolerances for out-of-round- 
ness and deflection. 

5. The operation of the closure 
device through its normal 
operating cycle should be 
observed while under control 
of the operator. This should 
indicate if the operator is fol- 
lowing posted procedures and 
if the operating procedures for 
the vessel are adequate. 

2) Gages, Safety Devices, and Controls 

a. The required pressure gage should 
be installed so that it is visible from 
the operating area located in such 
a way that the operator can accu- 
rately determine the pressure in the 
vessel while it is in operation. The 
gage dial size should be of such a 
diameter that it can be easily read 
by the operator. This gage should 
have a pressure range of at least 1 - 
1/2 times, but not more than four 
times, the operating pressure of the 
vessel. There should be no interven- 
ing valve between the vessel and 
gage. 



b. The pressure gage should be of a 
type that will give accurate read- 
ings, especially when there is a 
rapid change in pressure. It should 
be of rugged construction and 
capable of withstanding severe ser- 
vice conditions. Where necessary, 
the gage should be protected by a 
siphon or trap. 

c. Pressure gages intended to measure 
the operating pressure in the vessel 
are not usually sensitive or easily 
read at low pressures approaching 
atmospheric. It may be advisable to 
install an auxiliary gage that reads 
inches of water (mm of mercury) 
and is intended to measure pres- 
sure from atmospheric through low 
pressures. This gives assurance that 
there is zero pressure in the ves- 
sel before opening. It would be 
necessary to protect the auxiliary 
low pressure gage from the higher 
operating pressures. 

d. Provisions should be made to 
calibrate pressure gages or to have 
them checked against a master gage 
as frequently as necessary. 

e. A check should be made to ensure 
that the closure and its holding 
elements must be fully engaged in 
their intended operating position 
before pressure can be applied to 
the vessel. A safety interlock device 
should be provided that prevents 
the opening mechanism from oper- 
ating unless the vessel is completely 
depressurized. 

f. Quick-actuating closures held in 
position by manually operated 
locking devices or mechanisms, 
and which are subject to leakage of 
the vessel contents prior to disen- 
gagement of the locking elements 



44 



NATIONAL BOARD INSPECTION CODE • PART Z 



INSPECTION 



2.4 



2.4.1 



and release of the closure, shall be 
provided with an audible and/or 
visible warning device to warn the 
operator if pressure is applied to 
the vessel before the closure and 
its holding elements are fully en- 
gaged, and to warn the operator if 
an attempt is made to operate the 
locking device before the pressure 
within the vessel is released. Pres- 
sure tending to force the closure 
clear of the vessel must be released 
before the closure can be opened 
for access. 



PIPING AND PIPING SYSTEMS 



SCOPE 



This section provides guidelines for internal 
and external inspection of piping and piping 
systems. 



2.4.2 



SERVICE CONDITIONS 



a) Piping systems are designed for a variety of 
service conditions. The media that a piping 
system contains, the temperature at which 
it operates, and the piping corrosion history 
should be considered in establishing pip- 
ing inspection criteria. Particular attention 
should be given to piping systems that are 
subject to corrosion, high temperatures, 
and hazardous fluid or gasses. Piping op- 
erating beyond design temperature limits 
can cause sufficient deterioration of piping 
material properties due to graphitization, 
embrittlement, and creep to render the 
piping system unfit for continued service. 

b) Any externally or internally corroded pip- 
ing should be evaluated for integrity and 
repaired or replaced as necessary. 

c) Requirements specified for inspection ac- 
tivities and safety is identified in Section 



1 of this Part and should be reviewed and 
followed as applicable. 



2.4.3 ASSESSMENT OF PIPING 

DESIGN 

a) All pipe material and fittings should be 
properly rated for the maximum service 
conditions to which they are subjected 
under normal operating conditions and 
shall be provided with suitable relief device 
protection. The design corrosion allowance 
of the piping system should be considered 
when reviewing the current piping thick- 
ness data. 

b) If a piping system has a previous history of 
ultrasonic wall thickness measurements, 
the Inspector should review the data and 
request additional wall thickness measure- 
ments, if warranted. 



2.4.4 EXTERNAL INSPECTION OF 

PIPING 

Piping should be externally inspected for the 
following: 

a) Evidence of leakage. (See 2.4.6) 

b) Provision for expansion and adequate sup- 
port. (See 2.4.7) 

c) Proper alignment of piping joints and bolted 
connections. Check for missing bolts or 
studs, nuts, and improper or inadequate 
bolted connection thread engagement. Also 
check visible gasket and gasket alignment 
condition. Threaded connections should 
also be inspected for inadequate or exces- 
sive thread engagement. 

d) Past or present evidence of excessive vibra- 
tion or cyclic activity such as loose or miss- 
ing piping supports or piping insulation. If 
such activity is present, piping and piping 
joints should be inspected for potential 
fatigue cracking. 



45 



NATIONAL BOARD INSPECTION CODE • PART Z — INSPECTION 



e) Evidence of general corrosion, excessive 
external pitting, corrosion scale buildup, 
exfoliation, erosion, cuts, dents, distortion, 
or other detrimental conditions such as 
pipe sweating, water hammer damage, or 
hot spots. Ultrasonic thickness measure- 
ments should be taken in suspect areas 
to ensure adequate remaining piping wall 
thickness. 

f) Evidence of corrosion under piping insula- 
tion or other weather related damage to 
piping coatings. 

g) Evidence of freeze damage such as bulging, 
striations, or surface fissures. 

h) Dead leg or stagnant piping tends to have 
internal corrosion issues. Ultrasonic thick- 
ness measurements should be taken in sus- 
pect locations. Radiography is also useful 
to assess internal deposits and subsequent 
corrosion in no flow piping locations. 



2.4.5 INTERNAL INSPECTION OF 

PIPING 

a) Where the internal surfaces of piping, 
valves, and gasket surfaces are accessible 
to visual examination, internal inspection 
should include an examination of all avail- 
able surfaces. Nondestructive examina- 
tion for internal corrosion may be used to 
supplement the inspection. Boroscope or 
camera inspections are also useful to aug- 
ment piping internal inspections. 

b) Internal pipe surfaces should be cleaned 
before inspection, if necessary. 

c) The internal surfaces of piping, piping 
welds, and connections, fittings, valves, 
and gasket surfaces should be inspected for 
localized corrosion, pitting, erosion, blister- 
ing, cracking, and impingement damage. 



2.4.6 



EVIDENCE OF LEAKAGE 



a) A leak should be thoroughly investigated 
and corrective action initiated. Leaks 
beneath piping insulation should be ap- 
proached with caution, especially when 
removing insulation from a pressurized 
piping system for inspection. 

b) A pressure test may be required to obtain 
additional information regarding the extent 
of a defect or detrimental condition. 

c) To determine tightness, the test pressure 
need be no greater than the normal operat- 
ing pressure. The metal temperature should 
be not less than 70°F (21°C) and the maxi- 
mum metal temperature during inspection 
should not exceed 120°F (49°C). The po- 
tential corrosive effect of the test fluid on 
the piping material should be considered. 



2.4.7 PROVISIONS FOR EXPANSION 

AND SUPPORT 

a) Visual inspection should include a check 
for evidence of improper provision for 
piping expansion and support. Piping 
supports shall indicate loads within their 
design range. Piping supports should keep 
piping in alignment and prevent piping 
from colliding with other piping or station- 
ary objects. The alignment of connections 
between anchored equipment should be 
observed to determine if any change in po- 
sition of the equipment due to settling, ex- 
cessive cyclic activity, steady state stresses 
beyond design allowances, or other causes 
has placed an undue strain on the piping or 
its connections. Inadequate support or the 
lack of provision for expansion may cause 
broken attachment welds, cracks, or leak- 
age at fittings. Missing, damaged, or loose 
insulation materials may be an indication 
of vibration or pipe movements resulting 
from improper support. 



46 



NATIONAL BOARD INSPECTION CODE • PART Z — INSPECTION 



b) Piping support locations should be closely 
inspected at the support points for external 
and crevice corrosion concerns. 



2.4.8 



2.4.8.1 



INSPECTION OF GAGES, 
SAFETY DEVICES, AND 

CONTROLS 



GAGES 



Piping system pressure gages should be re- 
moved for testing unless there is other informa- 
tion to assess their accuracy. Faulty pressure 
gages should be recalibrated or replaced as 
necessary. 



2.4.8.2 SAFETY DEVICES 

See 2.5 for information on the inspection of 
pressure-relieving devices used to prevent the 
over pressure of piping systems. 



2.4.8.3 QUICK-DISCONNECT 
COUPLING 

Piping connections utilizing a quick-disconnect 
coupling should be checked to ensure that the 
coupling and its holding elements are fully 
engaged in their intended operating position. 
Means should be provided that warn the opera- 
tor against disengaging the coupling or prevent 
the opening mechanism from operating unless 
the piping is completely depressurized. 



2.5 



2.5.1 



PRESSURE RELIEF DEVICES 



SCOPE 



a) The most important appurtenances on any 
pressurized system are the pressure relief 
devices provided for overpressure protec- 
tion of that system. These are devices such 
as safety valves, safety relief valves, pilot 



valves, and rupture disks or other non- 
reclosing devices that are called upon to 
operate and reduce an overpressure condi- 
tion. 

b) These devices are not designed or intended 
to control the pressure in the system dur- 
ing normal operation. Instead, they are in- 
tended to function when normal operating 
controls fail or abnormal system conditions 
are encountered. 

c) Periodic inspection and maintenance of 
these important safety devices is critical to 
ensure their continued functioning and to 
provide assurance that they will be avail- 
able when called upon to operate. See 
2.5.8 for recommended testing frequency 
for PRDs. 

d) Inspection areas of concern include: 

1 ) correct set pressure; 

2) safety considerations; 

3) device data; 

4) condition of the device; 

5) condition of the installation; and 

6) testing and operational inspection. 



2.5.2 



PRESSURE RELIEF DEVICE DATA 



a) Nameplate marking or stamping of the 
device should be compared to stamping 
on the protected pressure-retaining item. 
For a single device, the set pressure shall 
be no higher than the maximum allowable 
working pressure (MAWP) marked on the 
protected pressure-retaining item or sys- 
tem. 

b) If multiple devices are provided, the differ- 
ence between set pressures shall not ex- 
ceed that permitted by the original code of 



47 



NATIONAL BOARD INSPECTION CODE • PART 2 



INSPECTION 



construction. The set pressure of additional 
devices may exceed the MAWP, as permit- 
ted by the original code of construction. 

c) Verify nameplate capacity and, if pos- 
sible, compare to system capacity require- 
ments. 

d) Check identification on seals and ensure 
they match nameplates or other identifica- 
tion (repair or reset nameplate) on the valve 
or device. 



2.5.3 CONDITIONS 

a) Check for evidence that the valve or device 
is leaking or not sealing properly. 

b) Seals for adjustments should be intact and 
show no evidence of tampering. 

c) Connecting bolting should be tight and all 
bolts intact. 

d) The valve or device should be examined 
for deposits or material buildup. 

e) Evidence of rust or corrosion should be 
checked. 

f) Check for damaged or misapplied parts. 

g) If a drain hole is visible, ensure it is not 
clogged with debris or deposits. 

h) Check for test gags left in place after pres- 
sure testing of the unit. 

i) Bellows valves shall be checked to ensure 
the bonnet vent is open or piped to a safe 
location. The vent shall not be plugged 
since this will cause the valve set pressure 
to be high if the bellows develops a leak. 
Leakage noted from the vent indicates the 
bellows is damaged and will no longer 
protect the valve from the effects of back 
pressure. 



2.5.4 INSERVICE INSPECTION 

REQUIREMENTS FOR PRESSURE 
RELIEF DEVICES 

a) Inspect inlet piping and ensure it meets the 
requirements of the original code of con- 
struction. For pressure relief valves, check 
that the inlet pipe size is not smaller than 
the device inlet size. 

b) Inspect discharge piping and ensure it 
meets the original code of construction. 
Check that the discharge pipe size is not 
smaller than the device outlet size. 

c) Check that the valve drain piping is open. 

d) Check drainage of discharge piping. 

e) Check that inlet and discharge piping are 
not binding or placing excessive stress on 
the valve body which can lead to distortion 
of the valve body and leakage or malfunc- 
tion. 

f) Check the condition and adequacy of 
piping supports. Discharge piping should 
be supported independent of the device 
itself. 

g) Check for possible hazards to personnel 
from the valve discharge or discharge 
pipe. 

h) Check that there are no intervening isola- 
tion valves between the pressure source 
and the valve inlet or between the valve 
outlet and its point of discharge. (Isolation 
valves may be permitted in some pressure 
vessel service. See Part 1, 5.3.6(e), and ju- 
risdictional requirements. Isolation valves 
are not permitted for power boilers, heating 
boilers, or water heaters.) 

i) A change-over valve, which is used to in- 
stall two pressure relief devices on a single 
vessel location for the purpose of switching 
from one device to a spare device, is not 
considered a block valve if it is arranged 



4-a 



NATIONAL BOARD INSPECTION CODE • PART Z 



INSPECTION 



such that there is no intermediate position 
that will isolate both pressure relief devices 
from the protected system. Change-over 
valves should be carefully evaluated to 
ensure they do not have excessive pres- 
sure drop that could affect the pressure 
relief device operation or capacity. These 
devices are commonly used in pressure ves- 
sel service. They may also be used in some 
boiler applications. It is recommended that 
the Jurisdiction be contacted to determine 
their acceptability on boiler applications. 



2.5.5 ADDITIONAL INSPECTION 

REQUIREMENTS 

Additional items should be considered for the 
specified services. 



2.5.5.1 



BOILERS 



a) If boilers are piped together with maximum 
allowable working pressures differing by 
more than six percent, additional protective 
devices may be required on the lower pres- 
sure units to protect them from overpressure 
from the higher pressure unit. 

b) Hot-Water Heating Boilers and Water Heaters 

1 ) These units general ly do not use any wa- 
ter treatment and therefore may be more 
prone to problems with deposits form- 
ing that may impair a safety device's 
operation. Particular attention should be 
paid to signs of leakage through valves 
or buildups of deposits. 

2) Hot-water boilers tend to have buildups 
of corrosion products since the system 
is closed with little makeup. These 
products can foul or block the valve 
inlet. 

3) Water heaters will have cleaner water 
due to continuous makeup. However, 
these valves usually have a thermal 



element that will cause the valve to 
open slightly when the water is heated 
and not removed from the system. 
When this hot water evaporates in the 
discharge piping, calcium deposits 
may tend to form in the valve inlet and 
outlet. 



2.5.5.2 PRESSURE VESSELS AND PIPING 

Standard practice for overpressure protection 
devices is to not permit any type of isolation 
valve either before or after the device. However, 
some pressure vessel standards permit isola- 
tion valves under certain controlled conditions 
when shutting clown the vessel to repair a dam- 
aged or leaking valve. If isolation block valves 
are employed, their use should be carefully 
controlled by written procedures. Block valves 
should have provisions to be either car-sealed 
or locked in an open position when not being 
used. For ASME Section VIII, Div. 1 pressure 
vessels, see UG-135, Appendix M, and juris- 
dictional rules for more information. 



2.5.5.3 



RUPTURE DISKS 



a) Rupture disks or other non-reclosing de- 
vices may be used as sole relieving devices 
or in combination with safety relief valves 
to protect pressure vessels. 

b) The selection of the correct rupture disk 
device for the intended service is critical 
to obtaining acceptable disk performance. 
Different disk designs are intended for 
constant pressure, varying pressure, or 
pulsating pressure. Some designs include 
features that make them suitable for back 
pressure and/or internal vacuum in the 
pressure vessel. 

c) The margin between the operating pressure 
and the burst pressure is an important fac- 
tor in obtaining acceptable performance 
and service life of the disk. Flat and pre- 
bulged solid metal disks are typically used 



49 



NATIONAL BOARD INSPECTION CODE ° PART 2 



INSPECTION 



with an operating pressure that is no more 
than 60% to 70% of the burst pressure. 
Other designs are available that increase 
the operating pressure to as much as 90% 
of the burst pressure. Disks that have been 
exposed to pressures above the normal op- 
erating pressure for which they are designed 
are subject to fatigue or creep and may fail 
at unexpectedly low pressures. Disks used 
in cyclic service are also subject to fatigue 
and may require a greater operating margin 
or selection of a device suitable for such 
service. 

d) The disk material is also critical to obtaining 
acceptable service life from the disk. Disks 
are available in a variety of materials and 
coatings, and materials that are unaffected 
by the process fluid should be used. Disks 
that experience corrosion may fail and 
open at an unexpectedly low pressure. 

e) Disk designs must also be properly selected 
for the fluid state. Some disk types are not 
suitable for use in liquid service. Some disks 
may have a different flow resistance when 
used in liquid service which may affect the 
sizing of the disk. 

f) Information from the rupture disk manufac- 
turer, including catalog data and installa- 
tion instructions, should be consulted when 
selecting a disk for a particular service. 

g) For rupture disks and other non-reclosing 
devices, the following additional items 
should be considered during inspections. 

1) The rupture disk nameplate informa- 
tion, including stamped burst pressure 
and coincident temperature, should be 
checked to ensure it is compatible with 
the intended service. The coincident 
temperature on the rupture disk shall 
be the expected temperature of the disk 
when the disk is expected to burst and 
will usually be related to the process 
temperature, not the temperature on 
the pressure vessel nameplate. 



2) Markings indicating direction of flow 
should be carefully checked to ensure 
they are correct. Some rupture disks 
when installed in the incorrect position 
may burst well above the stamped pres- 
sure. 

3) The marked burst pressure for a rupture 
disk installed at the inlet of a safety re- 
lief valve shall be equal to or less than 
the safety relief valve set pressure. A 
marked burst pressure of 90% to 1 00% 
of the safety relief valve set pressure 
is recommended. A disk with a non- 
fragmenting design that cannot affect 
the safety relief valve shall be used. 

Note: If the safety relief valve set pres- 
sure is less than the vessel MAWP, the 
marked burst pressure may be higher 
than the valve set pressure, but no 
higher than the MAWP. 

4) Check that the space between a rupture 
disk and a safety relief valve is sup- 
plied with a pressure gage, try cock, 
or telltale indicator to indicate signs of 
leakage through the rupture disk. The 
safety relief valve shall be inspected 
and the leaking disk shall be replaced if 
leakage through the disk is observed. 

5) If a rupture disk is used on a valve out- 
let, the valve design must be of a type 
not influenced by back pressure due to 
leakage through the valve. Otherwise, 
for nontoxic and non-hazardous fluids, 
the space between the valve and the 
ruptured disk shall be vented or drained 
to prevent the accumulation of pres- 
sure. 

6) For rupture disks installed on the valve 
inlet, the installation should be re- 
viewed to ensure that the combination 
rules of the original code of construc- 
tion have been applied. A reduction 
in the valve capacity up to 10% is 
expected when used in combination 
with a non-reclosing device. 



5D 



NATIONAL BOARD INSPECTION CODE • PART Z 



INSPECTION 



7) The frequency of inspection for rupture 
disks and other non-reclosing devices is 
greatly dependent on the nature of the 
contents and operation of the system 
and only general recommendations can 
be given. Inspection frequency should 
be based on previous inspection history. 
If devices have been found to be leak- 
ing, defective, or damaged by system 
contents during inspection, intervals 
should be shortened until acceptable 
inspection results are obtained. With 
this in mind, the inspection frequency 
guidelines specified in 2.5.8 are sug- 
gested for similar services. 

8) Rupture disks are often used to isolate 
pressure relief valves from services 
where fouling or plugging of the valve 
inlet occurs. This tendency should be 
considered in establishing the inspec- 
tion frequency. 

9) Since these devices are for one time 
use, a visual inspection is the only 
inspection that can be performed. 
Rupture disks that are installed using 
a specified bolting torque procedure 
cannot be reused after inspection and 
must be replaced. 

10) It is recommended that all disks be 
periodically replaced to prevent unin- 
tended failure while in service due to 
deterioration of the device. 



2.5.6 REQUIREMENTS FOR SHIPPING 

AND TRANSPORTING 

a) The improper shipment and transport of 
pressure relief devices can have detrimental 
effects on device operation. Pressure relief 
devices should be treated with the same 
precautions as instrumentation, with care 
taken to avoid rough handling or contami- 
nation prior to installation. 



b) The following practices are recommended: 

1 ) Flanged valves should be securely bolt- 
ed to pallets in the vertical position to 
avoid side loads on guiding surfaces. 

2) Threaded valves should be securely 
packaged and cushioned during trans- 
port. 

3) Valve inlet and outlet connection, drain 
connections, and bonnet vents should 
be protected during shipment and stor- 
age to avoid internal contamination of 
the valve. Ensure all covers and/or plugs 
are removed prior to installation. 

4) Lifting levers should be wired or se- 
cured so they cannot be moved while 
the valve is being shipped or stored. 
These wires shall be removed before 
the valve is placed in service. 

5) Rupture disks should be carefully 
checked for damage prior to installa- 
tion and handled by the disk edges, if 
possible. Any damage to the surface of 
the disk can affect the burst pressure. 



2.5.7 TESTING AND OPERATIONAL 

INSPECTION OF PRESSURE 
RELIEF DEVICES 

a) Pressure relief valves must be periodically 
tested to ensure that they are free to oper- 
ate and will operate in accordance with 
the requirements of the original code of 
construction. Testing should include device 
set or opening pressure, reclosing pres- 
sure, where applicable, and seat leakage 
evaluation. Tolerances specified for these 
operating requirements in the original code 
of construction shall be used to determine 
the acceptability of test results. 

b) Testing may be accomplished by the owner 
on the unit where the valve is installed or 
at a qualified test facility. In many cases, 



5 i 



NATIONAL BOARD INSPECTION CODE • PART Z 



INSPECTION 



c) 



testing on the unit may be impractical, es- 
pecially if the service fluid is hazardous or 
toxic. Testing on the unit may involve the 
bypassing of operating controls and should 
only be performed by qualified individuals 
under carefully controlled conditions. It is 
recommended that a written procedure be 
available to conduct this testing. 

1) The Inspector should assure that cali- 
brated equipment has been used to 
perform this test and the results should 
be documented by the owner. 

2) If the testing was performed at a test 
facility, the record of this test should 
be reviewed to ensure the valve meets 
the requirements of the original code of 
construction. Valves which have been 
in toxic, flammable, or other hazardous 
services shall be carefully decontami- 
nated before being tested. In particular, 
the closed bonnet of valves in these 
services may contain fluids that are not 
easily removed or neutralized. If a test 
cannot be safely performed, the valve 
shall be disassembled, cleaned, and 
decontaminated, repaired, and reset. 

3) If a valve has been removed for testing, 
the inlet and outlet connections should 
be checked for blockage by product 
buildup or corrosion. 

Valves may be tested using lift assist de- 
vices when testing at full pressure may 
cause damage to the valve being tested, 
or it is impractical to test at full pressure 
due to system design considerations. Lift 
assist devices apply an auxiliary load to 
the valve spindle or stem, and using the 
measured inlet pressure, applied load and 
other valve data al low the set pressure to be 
calculated. If a lift assist device is used to 
determine valve set pressure, the conditions 
of Part 3, Repairs and Alterations, Section 
4.5.3 shall be met. It should be noted that 
false set pressure readings may be obtained 



for valves which are leaking excessively or 
otherwise damaged. 

d) If valves are not tested on the system using 
the system fluid, the following test mediums 
shall be used: 

1) High pressure boiler safety valves, high 
temperature hot-water boiler safety re- 
lief valves, low pressure steam heating 
boilers: steam; 

2) Hot-water heating boiler safety relief 
valves: steam, air, or water; 

3) Hot water heater temperature and pres- 
sure relief valves: air or water; 

4) Air and gas service process safety relief 
valves: air, nitrogen, or other suitable 
gas; 

5) Liquid service process pressure relief 
valves: water or other suitable fluid; 

6) Process steam service safety relief 
valves: steam or air with manufacturer's 
steam to air correction factor. 

Note: Valves being tested after a repair 
must be tested on steam except as 
permitted by Part 3, Repairs and Altera- 
tions, Section 4.5.2. 

e) As an alternative to a pressure test, the valve 
may be checked by the owner for freedom 
of operation by activating the test or "try" 
lever (manual check). For high pressure 
boiler and process valves this test should 
be performed only at a pressure greater 
than 75% of the stamped set pressure of the 
valve or the lifting device may be damaged. 
This test will only indicate that the valve is 
free to operate and does not provide any 
information on the actual set pressure. All 
manual checks should be performed with 
some pressure under the valve in order to 
flush out debris from the seat that could 
cause leakage. 



52 



NATIONAL BOARD INSPECTION CODE • PART 2 — INSPECTION 



Note: The manual check at 75% or higher 
is based on lift lever design requirements 
for ASME Section I and VIII valves. Code 
design requirements for lifting levers for 
Section IV valves require that the valve be 
capable of being lifted without pressure. 

f) If a valve is found to be stuck closed, the 
system should immediately be taken out 
of service until the condition can be cor- 
rected, unless special provisions have been 
made to operate on a temporary basis (such 
as additional relief capacity provided by 
another valve). 

g) If a pressure test indicates the valve does 
not open within the requirements of the 
original code of construction, but otherwise 
is in acceptable condition, minor adjust- 
ments (defined as no more than twice the 
permitted set pressure tolerance) shall be 
made by an organization accredited by the 
National Board to reset the valve to the 
correct opening pressure. All adjustments 
shall be resealed with a seal identifying the 
responsible organization and a tag shall be 
installed identifying the organization and 
the date of the adjustment. 

h) If a major adjustment is needed, this may 
indicate the valve is in need of repair or has 
damaged or misapplied parts. Its condition 
should be investigated accordingly. 

i) Systems with multiple valves will require 
the lower set valves to be held closed to 
permit the higher set valves to be tested. 
A test clamp or "gag" should be used 
for this purpose. The spring compression 
screw shall not be tightened. It is recom- 
mended that the test clamps be applied in 
accordance with the valve manufacturer's 
instructions when the valve is at or near the 
test temperature, and be applied hand tight 
only to avoid damage to the valve stem or 
spindle. 

j) Upon completion of set pressure testing, 
all pressure relief valve gags shall be re- 
moved. 



2.5.8 RECOMMENDED INSPECTION 

AND TEST FREQUENCIES FOR 
PRESSURE RELIEF DEVICES 

a) Power Boilers 

1 ) Pressure less than 400 psig (2.76 MPa): 
Manual check every 6 months; pressure 
test annually to verify nameplate set 
pressure or as determined by operat- 
ing experience as verified by testing 
history. 

2) Pressure greater than 400 psig (2.76 
MPa): Pressure test to verify nameplate 
set pressure every three years or as 
determined by operating experience as 
verified by testing history. 

3) Pressure tests should be performed prior 
to bringing the boiler down for planned 
internal inspection so needed repairs 
or adjustments can be made while the 
boiler is down. 

b) High-Temperature Hot-Water Boilers 
Pressure test annually to verify nameplate 
set pressure or as determined by operating 
experience as verified by testing history. 
For safety reasons, removal and testing on 
a steam test bench is recommended. Such 
testing will avoid damaging the safety valve 
by discharge of a steam water mixture, 
which could occur if the valve is tested in 
place. 

c) Low-Pressure Steam Heating Boilers 
Manual check quarterly; pressure test annu- 
ally prior to steam heating season to verify 
nameplate set pressure. 

d) Hot-Water Heating Boilers 

Manual check quarterly; pressure test an- 
nually prior to heating season to verify 
nameplate set pressure. 

Note: The frequencies specified for the 
testing of pressure relief valves on boilers 
is primarily based on differences between 
high pressure boilers that are continuously 



53 



NATIONAL BOARD INSPECTION CDDE • PART 2 



INSPECTION 



manned, and lower pressure automatically 
controlled boilers that are not monitored 
by a boiler operator at all times. When 
any boiler experiences an overpressure 
condition such that the safety or safety 
relief valves actuate, the valves should be 
inspected for seat leakage and other dam- 
age as soon as possible and any deficiencies 
corrected. 

Water Heaters 

Manual check every two months. Due to 
the relatively low cost of safety valves for 
this service, it is recommended that a defec- 
tive valve be replaced with a new valve if 
a repair or resetting is indicated. 

Pressure Vessels and Piping 
Frequency of test and inspection of pres- 
sure relief devices for pressure vessel and 
piping service is greatly dependent on the 
nature of the contents and operation of the 
system and only general recommendations 
can be given. Inspection frequency should 
be based on previous inspection history. If 
valves are found to be defective or damaged 
by system contents during inspection, inter- 
vals should be shortened until acceptable 
inspection results are obtained. Where test 
records and/or inspection history are not 
available, the following inspection and test 
frequencies are suggested. 



Service 


Inspection Frequency 


Steam 


Annual 


Air and Clean Dry 
Cases 


Every three years 


Pressure relief valves 
in combination with 
rupture disks 


Every five years 


Propane, Refrigerant 


Every five years 


All Others 


Per inspection history 



g) Establishment of Inspection and Test Inter- 
vals 

Where a recommended test frequency is 
not listed, the valve user and Inspector must 



determine and agree on a suitable interval 
for inspection and test. Some items to be 
considered in making this determination 
are: 

1) Jurisdictional requirements; 

2) Records of test data and inspections 
from similar processes and similar de- 
vices in operation at that facility; 

3) Recommendations from the device 
manufacturer. In particular, when the 
valve includes a non-metallic part such 
as a diaphragm, periodic replacement 
of those parts may be specified; 

4) Operating history of the system. Sys- 
tems with frequent upsets where a valve 
has actuated require more frequent 
inspection; 

5) Results of visual inspection of the de- 
vice and installation conditions. Signs 
of valve leakage, corrosion or damaged 
parts all indicate more frequent opera- 
tional inspections; 

6) Installation of a valve in a system with 
a common discharge header. Valves 
discharging into a common collection 
pipe may be affected by the discharge 
of other valves by the corrosion of parts 
in the outlet portion of the valve or the 
buildup of products discharged from 
those valves; 

7) Ability to coordinate with planned 
system shutdowns. The shutdown of 
a system for other maintenance or in- 
spection activities is an ideal time for 
the operational inspection and test of 
a pressure relief valve; 

8) Critical nature of the system. Systems 
that are critical to plant operation or 
where the effects of the discharge of 
fluids from the system are particularly 



54 



NATIONAL BOARD INSPECTION CODE • PART Z 



INSPECTION 



detrimental due to fire hazard, environ- 
mental damage, or toxicity concerns 
all call for more frequent inspection 
intervals to ensure devices are operat- 
ing properly; 

9) Where the effects of corrosion, block- 
age by system fluid, or ability of the 
valve to operate under given service 
conditions are unknown (such as in 
a new process or installation), a rela- 
tively short inspection interval, not to 
exceed one year or the first planned 
shutdown, whichever is shorter, shall 
be established. At that time the device 
shall be visually inspected and tested. If 
unacceptable test results are obtained, 
the inspection interval shall be reduced 
by 50% until suitable results are ob- 
tained. 



3) 



also well advised preventative mainte- 
nance activities that can prevent future 
problems. If the valve is serviced, a 
complete disassembly, internal inspec- 
tion, and repair as necessary, such that 
the valve's condition and performance 
are restored to a like new condition, 
should be done by an organization ac- 
credited by the National Board. 

Service records with test results and 
findings should be maintained for all 
over pressure protection devices. A 
service interval of no more than three 
inspection intervals or ten years, which- 
ever is less, is recommended to main- 
tain device condition. Results of the 
internal inspection and maintenance 
findings can then be used to establish 
future service intervals. 



h) Establishment of Service Intervals 

1) The above intervals are guidelines for 
periodic inspection and testing. Typi- 
cally if there are no adverse findings, a 
pressure relief valve would be placed 
back in service until the next inspec- 
tion. Any unacceptable conditions 
that are found by the inspection shall 
be corrected immediately by repair or 
replacement of the device. Many us- 
ers will maintain spare pressure relief 
devices so the process or system is not 
affected by excessive downtime. 

2) Pressure relief valves are mechanical 
devices that require periodic preven- 
tive maintenance even though external 
inspection and test results indicate ac- 
ceptable performance. There may be 
wear on internal parts, galling between 
sliding surfaces or internal corrosion, 
and fouling which will not be evident 
from an external inspection or test. 
Periodic re-establishment of seating sur- 
faces and the replacement of soft goods 
such as O-rings and diaphragms are 



55 



NATIONAL BOARD INSPECTION CODE • PART 2 — INSPECTION 



56 



■ 



Insert 

Section 3 
Tab 

Here 



■ I 



I i 




Part Z, Section 3 

Inspection — Corrosion and Failure 
Mechanisms 



57 



NATIONAL BDARD INSPECTION CODE • PART 2 



INSPECTION 



PART 2, SECTION 3 
INSPECTION — CORROSION AND FAILURE MECHANISMS 



3.1 SCOPE 

a) This section describes damage mechanisms 
applicable to pressure-retaining items. Fur- 
ther information concerning metallurgical 
properties of steels and nonferrous alloys are 
described in ASME Section II, Part D, of the 
Boiler and Pressure Vessel Code, Appendix 
6, titled Metallurgical Phenomena. 

b) A damage (or deterioration) mechanism is a 
process that induces deleterious micro and 
or macro material changes over time that 
are harmful to the material condition or me- 
chanical properties. Damage mechanisms 
are usually incremental, cumulative and, in 
some instances, unrecoverable. Common 
damage mechanisms include corrosion, 
chemical attack, creep, erosion, fatigue, 
fracture, and thermal aging. 



3.2 



GENERAL 



Understanding the potential damage/deteriora- 
tion mechanisms that can affect the mechani- 
cal integrity of a pressure-retaining item and 
knowledge of the inspection methods that can 
be used to find these damage mechanisms are 
essential to an effective inspection. This sec- 
tion includes a general discussion of various 
damage mechanisms and effective inspection 
methods are referenced in Section 4 of this Part. 
In addition, some specific guidance is given on 
how to estimate the remaining life of a pressure- 
retaining item and determine the appropriate 
inspection frequencies as referenced in Section 
5 of this Part. 



3.3 



CORROSION 



All metals and alloys are susceptible to cor- 
rosion. Corrosion is deterioration that occurs 



when a metal reacts with its environment. 
Corrosion can be classified based on three 
factors: 

a) Nature 

1) wet — liquid or moisture present 

2) dry — high temperature gasses 

b) Mechanism — electrochemical or direct 
chemical reactions 

c) Appearance — either uniform or local- 
ized 



3.3.1 MACROSCOPIC CORROSION 

ENVIRONMENTS 

Macroscopic corrosion types are among the 
most prevalent conditions found in pressure- 
retaining items causing deterioration. The fol- 
lowing corrosion types are found. 

a) Uniform Corrosion (General) 

The most common form of corrosion is 
uniform attack over a large area of the 
metal surface. Safe working pressure is 
directly related to the remaining material 
thickness, and failures can be avoided by 
regular inspection. 

b) Galvanic Corrosion 

Two dissimilar metals in contact with each 
other and with an electrolyte (i.e., a film 
of water containing dissolved oxygen, 
nitrogen, and carbon dioxide) constitute 
an electrolytic cell, and the electric cur- 
rent flowing through the circuit may cause 
rapid corrosion of the less noble metal (the 
one having the greater electrode potential). 
This corrosion mechanism is most active 
when there are large differences between 



5B 



NATIONAL BOARD INSPECTION CODE • PART 2 



INSPECTION 



the electrode potentials of the two metals, 
but galvanic corrosion may also exist with 
relatively minor changes of alloy compo- 
sition (i.e., between a weld metal and the 
base metal). Natural (i.e., an oxide coating 
on aluminum) or protective coatings may 
inhibit galvanic corrosion, but in most 
instances the metals or alloys must be se- 
lected on the basis of intrinsic resistance 
to corrosion. In pressure vessels the effects 
of galvanic corrosion are most noticeable 
at rivets, welds, or at flanged and bolted 
connections. 

c) Erosion Corrosion 

Movement of a corrosive over a metal 
surface increases the rate of attack due to 
mechanical wear and corrosion. This cor- 
rosion is generally characterized as having 
an appearance of smooth bottomed shal- 
low pits and may also exhibit a directional 
pattern related to the path taken by the 
corrosive. 

d) Crevice Corrosion 

Environmental conditions in a crevice can, 
with time, become different to those on a 
nearby clean surface. A more aggressive en- 
vironment may develop within the crevice 
and cause local corrosion. Crevices com- 
monly exist at gasket surfaces, lap joints, 
bolts, rivets, etc. They are also created by 
dirt deposits, corrosion products, scratches 
in paint, etc. Crevice corrosion is usually at- 
tributed to one or more of the following: 

1) Changes in acidity in the crevice; 

2) Lack of oxygen in the crevice; 

3) Buildup of detrimental ions in the crev- 
ice; and 

4) Depletion of a corrosion inhibitor in 
the crevice. 

e) Pitting Corrosion 

Pitting corrosion is the formation of holes in 
an otherwise relatively unattacked surface. 



Pitting is usually a slow process causing 
isolated, scattered pitting over a small area 
that does not substantially weaken the ves- 
sel. It could, however, eventually cause 
leakage. 

f) Line Corrosion 

This is a condition where pits are con- 
nected, or nearly connected, to each other 
in a narrow band or line. Line corrosion 
frequently occurs in the area of intersection 
of the support skirt and the bottom of the 
vessel or liquid-vapor interface. 

g) Exfoliation 

Exfoliation is a subsurface corrosion that 
begins on a clean surface but spreads 
below it. It differs from pitting in that the 
attack has a laminated appearance. These 
attacks are usually recognized by a flaky 
and sometimes blistered surface. 

h) Selective Leaching 

Selective leaching is the removal of one ele- 
ment in an alloy. This corrosion mechanism 
is detrimental because it yields a porous 
metal with poor mechanical properties. 

i) Grooving 

This type of corrosion is a form of metal 
deterioration caused by localized cor- 
rosion and may be accelerated by stress 
concentration. Grooving may be found 
adjacent to riveted lap joints or welds and 
on flanged surfaces, particularly the flanges 
of un-stayed heads. 



3.3.2 MICROSCOPIC CORROSION 

ENVIRONMENTS 

Microscopic corrosion environments are not 
visible to the naked eye. The following cor- 
rosion types are among the most prevalent 
conditions found in pressure-retaining items 
causing deterioration. 

a) Intergranular Corrosion 

Corrosion attack by a corrosive usually re- 



59 



NATIONAL BOARD INSPECTION CODE • PART 2 



INSPECTION 



lated to the segregation of specific elements 
or the formation of a compound in the 
grain boundary. It usually attacks the grain 
boundary that has lost an element neces- 
sary for adequate corrosion resistance. In 
severe cases entire grains are dislodged 
causing the surface to appear rough to the 
naked eye and will feel sugary because 
of the loose grains. Susceptibility to inter- 
granular corrosion is usually a by-product 
of heat treatment. 

b) Stress Corrosion Cracking (SCC) 

1) The action of tensile stress and a cor- 
rosive result in the cracking of metals. 
This is most serious because periods 
of time (often years) may pass before 
cracks become visible. The cracks then 
propagate quite rapidly and result in 
unexpected failures. Stresses that cause 
cracking arise from cold working, 
welding, thermal treatment, or may 
be externally applied during service. 
The cracks can follow intergranular or 
transgranular paths and often have a 
tendency for branching. 

2) The principal variables affecting stress 
corrosion cracking are tensile stress, 
service temperature, solution chem- 
istry, duration of exposure, and metal 
properties. Modifying any one of these 
parameters sufficiently can reduce or 
eliminate the possibility of stress corro- 
sion cracking occurring in service. As 
an example, austenitic stainless steels 
used in water wetted service are sus- 
ceptible to stress corrosion cracking. 

c) Corrosion Fatigue 

This is a special form of stress corrosion 
cracking caused by repeated cyclic stress- 
ing. When fatigue is in the presence of a 
corrodent, the result is corrosion fatigue. 
Such damage is common to pressure- 
retaining items subjected to continuous 
vibration. 



3.3.3 



CONTROL OF CORROSION 



There are many ways to control and avoid 
corrosion such as control of process variables, 
engineering design, protection, material selec- 
tion, and coatings. 



3.3.3.1 PROCESS VARIABLES 

Some of the more common process variables 
that influence corrosion are listed below: 

a) Concentration of major constituents 

b) Impurities 

c) Temperature 

d) pH 

e) Velocity 

f) Inhibitors 

g) Start-up and downtime operations 



3.3.3.2 



PROTECTION 



Protective methods such as cathodic and an- 
odic corrosion control can minimize attack and 
thereby reduce replacement costs or permit the 
use of less expensive or thinner materials. 



3.3.3.3 



MATERIAL SELECTION 



Chemical and physical properties of a mate- 
rial will enable selection of the best one for a 
specific application. The final choice will often 
be a compromise between the desired physical 
properties and economic factors. A checklist for 
material selection would include: 

a) Evaluating requirements to be met (prop- 
erties, design, appearance, mechanical, 
physical) 



6D 



NATIONAL BOARD INSPECTION CODE " PART 2 — INSPECTION 



b) Material selection considerations 

c) Corrosive variables 

d) Application of equipment 

e) Experience of materials 

3.3.3.4 COATINGS 

Metallic and inorganic materials are typical 
coatings for controlling corrosion. Selection 
of materials depends on the corrosive, method 
of application, type of base material, and the 
nature of bonding between the base material 
and coating. The success or failure of a coating 
will often depend on the surface preparation. 

a) Techniques for applying metallic coatings 
could include: 

1) Hot dipping 

2) Metal spraying 

3) Cladding 

4) Cementation 

5) Vapor deposition 

6) Electroplating 

7) Plating 

8) Welding 

b) Techniques for applying inorganic coatings 
would include: 

1) Porcelain, ceramic 

2) Glass 

3) Cement 

4) Rubber 



5) Paint 

6) Phosphates 



3.3.3.5 



ENGINEERING DESIGN 



Crevice, galvanic, erosion, and stress corro- 
sion cracking are the types of corrosion most 
controllable by proper design of equipment. 
Procedures and situations such as welding, end- 
grain attack, and drainage are also controlled 
by proper design techniques. 



3.3.3.6 



CONCLUSION 



a) By carefully selecting materials and protec- 
tion methods, we can predict and control 
corrosive attack. However, there may be 
unexpected damage as a result of one or 
more of the following: 

1 ) Poor choice of materials 

2) Operating conditions different from 
those anticipated 

3) Defective fabrication 

4) Improper design 

5) Inadequate maintenance 

6) Defective material 

b) Corrective actions will depend on which 
factors caused the problems making it im- 
portant to diagnose the reason for damage. 
Early detection of corrosion problems is 
important to prevent further damage and 
can be achieved by performing regular 
inspections and encouraging employees 
to be observant and communicate their 
observations. 



e i 



NATIONAL BOARD INSPECTION CODE * PART Z 



INSPECTION 



3.4 



FAILURE MECHANISMS 



The following failure mechanism information 
may assist inspectors in identifying service 
induced deterioration and failure modes en- 
countered in pressure-retaining items. 



3.4.1 



FATIGUE 



Stress reversals (such as cyclic loading) in parts 
of equipment are common, particularly at 
points of high secondary stress. If stresses are 
high and reversals frequent damage may occur 
because of fatigue. Fatigue damage in pressure 
vessels may also result from cyclic temperature 
and pressure changes. Locations where metals 
having different thermal coefficients of expan- 
sion are joined by welding may be susceptible 
to thermal fatigue. 



3.4.2 



CREEP 



Creep damage may occur if equipment is 
subjected to temperatures above those for 
which the equipment is designed. Since metals 
become weaker at higher temperatures, such 
distortion may result in failure, particularly 
at points of stress concentration. If excessive 
temperatures are encountered, structural prop- 
erty and chemical changes in metals may also 
take place, which may permanently weaken 
equipment. Since creep is dependent on time, 
temperature and stress, the actual or estimated 
levels of these quantities should be used in any 
evaluations. 



3.4.3 



TEMPERATURE EFFECTS 



At subfreezing temperatures, water and some 
chemicals handled in pressure vessels may 
freeze and cause damage. Carbon and low al- 
loy steels may be susceptible to brittle failure 
at ambient temperatures. A number of failures 
have been attributed to brittle fracture of steels 
that were exposed to temperatures below their 



transition temperature and that were exposed 
to pressures greater than 20% of the required 
hydrostatic test pressure. However, most brittle 
fractures have occurred on the first applica- 
tion of a particular stress level (that is, the first 
hydrostatic test or overload). Special attention 
should be given to low alloy steels because 
they are prone to temper embrittlement. Temper 
embrittlement is defined as a loss of ductility 
and notch toughness due to postweld heat 
treatment or high temperature service, above 
700°F(371°C). 



3.4.4 



HYDROGEN EMBRITTLEMENT 



a) The term hydrogen embrittlement (HE) re- 
fers to a loss of ductility and toughness in 
steels caused by atomic hydrogen dissolved 
in the steel. Hydrogen that is dissolved in 
carbon and low alloy steels from steel mak- 
ing, welding, or from surface corrosion can 
cause either intergranular or transgranular 
cracking and "brittle" fracture behavior 
without warning. 

b) Hydrogen embrittlement typically occurs 
below 200°F (93°C) because hydrogen re- 
mains dissolved within the steel at or below 
this temperature. One example of hydrogen 
embrittlement is underbead cracking. The 
underbead cracks are caused by the ab- 
sorption of hydrogen during the welding 
process in the hard, high strength weld heat 
affected zone (HAZ). Use of low hydrogen 
welding practices to minimize dissolved 
hydrogen and/or the use of high preheat, 
and/or postweld heat treatment can reduce 
susceptibility to cracking from hydrogen 
embrittlement. The diffusivity of hydrogen 
is such that at temperatures above 450°F 
(232°C), the hydrogen can be effectively 
removed eliminating susceptibility to crack- 
ing. Thus, hydrogen embrittlement may be 
reversible as long as no physical damage 
(e.g., cracking or fissures), has occurred in 
the steel. 



62 



NATIONAL BOARD INSPECTION CODE • PART 2 — INSPECTION 



c) Hydrogen embrittlement is a form of stress 
corrosion cracking (SCC). Three basic 
elements are needed to induce SCC: the 
first element is a susceptible material, the 
second element is environment, and the 
third element is stress (applied or residual). 
For hydrogen embrittlement to occur, the 
susceptible material is normally higher 
strength carbon or low alloy steels, the en- 
vironment must contain atomic hydrogen, 
and the stress can be either service stress 
and/or residual stress from fabrication. If 
any of the three elements are eliminated, 
HE cracking is prevented. 

d) In environments where processes are 
conducted at elevated temperature, the 
reaction of hydrogen with sulfur in carbon 
and low alloy reactor vessel steels can 
produce hydrogen sulfide stress corro- 
sion (SSC), which is a form of hydrogen 
embrittlement. Susceptibility to sulfide 
stress corrosion cracking depends on the 
strength of the steel. Higher strength steels 
are more susceptible. The strength level at 
which susceptibility increases depends on 
the severity of the environment. Hydrogen 
sulfide, hydrogen cyanide, and arsenic in 
aqueous solutions, all increase the sever- 
ity of the environment towards hydrogen 
embrittlement by increasing the amount 
of hydrogen that can be absorbed by the 
steel during the corrosion reaction. In hy- 
drogen sulfide environments, susceptibility 
to cracking can be reduced by using steels 
with a strength level below that equivalent 
to a hardness of 22 on the Rockwell C 
scale. 

e) Other forms of hydrogen embrittlement are 
wet hydrogen sulfide (H 2 S) cracking, hy- 
drogen stress cracking, hydrogen-induced 
cracking (HIC), and stress-oriented hydro- 
gen-induced cracking (SOHIC). In each 
case, three basic elements are required for 
this damage mechanism — susceptible ma- 
terial, hydrogen generating environments, 
and stress (either residual or applied). Or- 



ganic or inorganic coatings, alloy cladding 
or linings, are often used as a barrier to 
mitigate wet H 2 S corrosion and subsequent 
cracking. 



3.4.5 HIGH TEMPERATURE 

HYDROGEN ATTACK 

a) Hydrogen attack is a concern primarily in 
refinery and petrochemical plant equip- 
ment handling hydrogen and hydrogen- 
hydrocarbon streams at temperatures above 
450°F (232°C) and pressure above 100 
psi (700 kPa). A guideline for selection of 
steels to avoid hydrogen attack is given in 
API Publication 941, "Steels for Hydro- 
gen Service at Elevated Temperatures and 
Pressures in Petrochemical Refineries and 
Petrochemical Plants." Also widely known 
as the "Nelson Curves," API 941 shows that 
the severity of hydrogen attack depends on 
temperature, hydrogen partial pressure, 
exposure time, and steel composition. 
Additions of chromium and molybdenum 
increase resistance to hydrogen attack. It 
is important to understand that hydrogen 
attack is different from hydrogen embrittle- 
ment, which is discussed in 3.4.4. 

b) Hydrogen attack occurs in a high tempera- 
ture, high pressure hydrogen environment 
that can degrade the mechanical strength 
of carbon and low alloy steels. The dam- 
age is caused by hydrogen permeating into 
the steel and reacting with carbon to form 
methane. Since carbon is an element that 
strengthens steel, its removal by the high 
temperature reaction with hydrogen causes 
the steel to lose strength. In addition, meth- 
ane can become trapped within the steel at 
high pressures, eventually forming bubbles, 
fissures (cracks), and/or blisters. 

c) Damage caused by hydrogen attack is 
preceded by an incubation period with 
no noticeable change in properties. After 
the incubation period, decarburization 



63 



NATIONAL BOARD INSPECTION CODE • PART 2 



INSPECTION 



and/or blistering and Assuring will occur. 
The length of the incubation period var- 
ies with service temperature, the partial 
pressure of hydrogen, and alloy content of 
the steel. Damage is reversible during the 
incubation period, during which no loss of 
mechanical properties will have occurred. 
Once permanent degradation begins, the 
damage is irreversible. 



3.4.6 



HYDROGEN DAMAGE 



a) Hydrogen damage has been encountered 
in steam boilers that operate in the high 
pressure range (1200 psi [8.27 MPa] or 
higher), with relatively high purity boiler 
feed water. In boilers, the mechanism of 
hydrogen damage is initiated by underde- 
posit corrosion on water-touched surfaces. 
During operation of the boiler, waterwall 
tubing exposed to high heat flux can result 
in a departure from nucleate boiling (DNB) 
condition on the ID (waterside) surface due 
to small flow disturbances. Because of the 
increased tube metal temperature, low lev- 
els of contaminants in the boiler feedwater 
precipitate (e.g., plate out) on the hot tube 
surface. The intermittent wetting from flow, 
over time, results in the accumulation of 
deposits. 

b) As the deposit begins to thicken, the tube 
metal beneath the deposit locally increases 
in temperature causing oxidation of the 
tube metal. The oxidation/reduction corro- 
sion mechanism creates atomic hydrogen 
which permeates into the tube wall at boiler 
pressures greater than 1200 psig (8.27 
MPa). 

c) The atomic hydrogen reacts with the car- 
bon in the steel forming methane gas that 
results in microfissures at grain boundaries 
and decarburization. The combination of 
decarburization and microcracks increases 
the susceptibility to brittle fracture in ser- 
vice. The typical appearance of hydrogen 



damage in boiler tubes is a thick-lipped, 
"window-type" blow out of tube metal. 

d) Hydrogen damage in copper and copper 
alloys has also been observed and is some- 
times known as steam embrittlement. This 
type of damage commonly occurs when 
the copper contains oxygen. Hydrogen 
entering the metal reacts with the oxygen to 
form water. At certain combinations of pres- 
sures and temperatures steam forms and the 
pressure generated is sufficient to produce 
micro-cavity formation and cracking. 



3.4.7 



BULGES AND BLISTERS 



a) A bulge may be caused by overheating of 
the entire thickness of the metal, thereby 
lowering the strength of the metal which 
is then deformed by the pressure. Bulges 
may also be caused by creep or temperature 
gradients. 

b) A blister may be caused by a defect in the 
metal such as a lamination where the side 
exposed to the fire overheats but the other 
side retains its strength due to cooling effect 
of water or other medium. Blisters may also 
be caused by a hydrogen environment. (See 
3.4.5) 



3.4.8 



OVERHEATING 



a) Overheating is one of the most serious 
causes of deterioration. Deformation and 
possible rupture of pressure parts may re- 
sult. 

b) Attention should be given to surfaces that 
have either been exposed to fire, or exposed 
to operating temperatures that exceed their 
design limit. It should be observed whether 
any part has become deformed due to 
bulging or blistering. If a bulge or blister 
reduces the integrity of the component or 
when evidence of leakage is noted coming 
from those defects, proper repairs must be 
made. 



64 



NATIONAL BOARD INSPECTION CODE • PART 2 — INSPECTION 



3.4.9 CRACKS 

a) Cracks may result from flaws existing in ma- 
terial or excessive cyclic stresses. Cracking 
can be caused by fatigue of the metal due 
to continual flexing and may be accelerated 
by corrosion. Fire cracks are caused by the 
thermal differential when the cooling effect 
of the water is not adequate to transfer the 
heat from the metal surfaces exposed to the 
fire. Some cracks result from a combination 
of all these causes mentioned. 

b) Cracks noted in shell plates and fire cracks 
that run from the edge of the plate into the 
rivet holes of girth seams should be re- 
paired. Thermal fatigue cracks determined 
by engineering evaluation to be self arrest- 
ing may be left in place. 

c) Areas where cracks are most likely to ap- 
pear should be examined. This includes 
the ligaments between tube holes, from 
and between rivet holes, any flange where 
there may be repeated flexing of the plate 
during operation and around welded con- 
nections. 

d) Lap joints are subject to cracking where the 
plates lap in the longitudinal seam. If there 
is any evidence of leakage or other distress 
at this point, the Inspector shall thoroughly 
examine the area and, if necessary, have 
the plate notched or slotted in order to de- 
termine whether cracks exist in the seam. 
Repairs of lap joint cracks on longitudinal 
seams are prohibited. 

e) Where cracks are suspected, it may be 
necessary to subject the pressure-retaining 
item to a hydrostatic test or nondestructive 
examination to determine their presence 
and location. 

f) Cracks shall either be repaired, or formally 
evaluated by Crack Propagation Analysis to 
quantify their existing mechanical integ- 
rity. 



65 



NATIDNAL BOARD INSPECTION CODE • PART Z — INSPECTION 



66 



Insert 

Section 4 
Tab 

Here 




wWmm 





Part 2, Section 4 
Inspection — Examinations, 
Test Methods, and Evaluations 



&v 



NATIONAL BOARD INSPECTION CODE • PART 2 — INSPECTION 



INSPECTION 



PART 2, SECTION 4 
EXAMINATIONS, TEST METHODS, AND EVALUATIONS 



4.1 



SCOPE 



This section describes acceptable examination 
and test methods that are available to the In- 
spector during inspection of pressure-retaining 
items. This section also describes evaluation of 
test results and assessment methodologies. 



4.2 NONDESTRUCTIVE 

EXAMINATION METHODS 
(NDE) 

a) Listed below is a variety of nondestruc- 
tive examination methods that may be 
employed to assess the condition of pres- 
sure-retaining items. The skill, experience, 
and integrity of the personnel performing 
these examinations are essential to obtain 
meaningful results. The Inspector should 
review the methods and procedures to be 
employed to assure compliance with juris- 
dictional requirements. 

b) Generally, some form of surface preparation 
will be required prior to use of these exami- 
nation methods. When there is doubt as to 
the extent of a defect or detrimental condi- 
tion found in a pressure-retaining item, the 
Inspector is cautioned to seek competent 
technical advice and supplemental NDE. 

c) Personnel performing examination and test 
methods shall have proper training and cer- 
tification, as required by the owner and is 
acceptable to the Inspector and Jurisdiction, 
if required. 



4.2.1 



VISUAL 



Visual examination is the basic method 
used when conducting an inservice inspec- 
tion of pressure-retaining items. Additional 



examination and test methods may be re- 
quired at the discretion of the inspector to 
provide additional information to assess the 
condition of the pressure-retaining item. 

b) Visual examination is an inspection method 
to ascertain the surface condition of the 
pressure-retaining item. The Inspector 
should be aware of recognizing various 
surface features and comparing these fea- 
tures with damage mechanisms listed in 
Section 3 of this Part that could indicate 
exposure of the pressure-retaining item to 
harmful corrosion or elevated temperature 
service. 

c) In some cases the Inspector may have 
limited or no access while performing an 
inspection of the pressure-retaining item. 
Subject to approval of the Jurisdiction, 
remote camera or fiber optic devices may 
be considered acceptable methods to view 
and record the surface condition of the 
pressure-retaining item. 



4.2.2 



MAGNETIC PARTICLE 



a) The magnetic particle examination method 
can be used only on ferromagnetic materi- 
als to reveal surface discontinuities and to 
a limited degree, those located below the 
surface. It uses the principle that magnetic 
lines of force will attract magnetizable 
material. The sensitivity of this method 
decreases rapidly with depth below the 
surface being examined and, therefore, it 
is used primarily to examine for surface 
discontinuities. 

b) In order to use this method, a magnetic field 
has to be established within the material to 
be examined. This can be done directly by 
bringing a strong magnetic field into close 



63 



NATIONAL BDARD INSPECTION CODE • PART 2 — INSPECTION 



proximity of the item being examined or 
by inducing a magnetic field in the object 
by passing electric current through the 
object. 

c) If there is a discontinuity at or near the 
surface, it will deflect the magnetic lines of 
force out of the object, thus creating a north 
pole (magnetic lines leave the north pole of 
a magnet). The magnetic lines offeree will 
re-enter the test object on the other side of 
the discontinuity, thereby creating a south 
pole (magnetic lines enter the south pole of 
a magnet). Since a north and a south pole 
have been created they will attract magne- 
tizable objects. Iron powder placed on the 
discontinuity is held in place by the lines 
offeree and will be visible on the surface 
of the test object. 



4.2.4 



ULTRASONIC 



Ultrasonic testing is used for volumetric exami- 
nation of welds and base materials (metallic 
and nonmetallic) for detection of flaws. This 
method depends on sound waves of very high 
frequency being transmitted through metal 
and reflected at any boundary, such as a metal 
to air boundary at the surface of the metal or 
metal crack boundary at a discontinuity. High 
frequency sound waves can detect small ir- 
regularities but are easily absorbed, particularly 
by coarse-grained materials. Sound waves can 
be introduced into a part either normal to the 
surface or at predetermined angles. Factors such 
as material composition, surface condition, 
choice of equipment, and ability of the opera- 
tor affect the results of ultrasonic inspection. 
Ultrasonic testing can also be used to measure 
material thickness. 



4.2.3 



LIQUID PENETRANT 



4.2.5 



RADIOGRAPHY 



a) The liquid penetrant examination method is 
used to detect discontinuities that are open 
to the surface of the material being exam- 
ined. This method may be used on both 
ferrous and nonferrous materials. Liquid 
penetrant examination may be used for the 
detection of surface discontinuities such as 
cracks, seams, laps, cold shuts, laminations, 
and porosity. 

b) Liquid penetrant examination works by 
applying a colored liquid (penetrant) to 
the object to be examined. Time is allowed 
for the liquid to fill any voids that are open 
to the surface. Excess penetrant is then 
removed and a "developer" is applied in a 
uniform, thin coating. The developer acts 
as a blotter and draws the penetrant out of 
the discontinuity. The developer is usually 
of a contrasting color to the penetrant. The 
penetrant indications will appear as colored 
figures on a background of the developer. 

c) Liquid penetrant examination is portable, fast, 
and requires minimal operator training. 



a) Radiography is a volumetric method that 
can detect discontinuities throughout a 
material. This method is commonly used 
to examine for surface and subsurface 
discontinuities. The use of this method 
may be restricted due to the configuration 
of the welded joint or the limitations of 
the radiographic equipment. Radiography 
will not give an indication of the depth of 
discontinuity unless special procedures are 
used. 

b) The method uses a high energy gamma ray 
or x-ray source to penetrate the material to 
be examined. The rays are absorbed, reflect- 
ed, and refracted by the material, but some 
of the energy passes completely through. 
The energy of rays that pass completely 
through is determined by the thickness and 
other physical properties of the material. 

c) Radiography uses film to detect the rays 
that penetrate the material. The higher the 
energy of the rays, the darker the film will 
become, similar to exposing photographic 
film to sunlight. 



69 



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INSPECTION 



d) Most discontinuities (cracks, porosity, and 
inclusions) reduce the amount of base 
material available to absorb (attenuate) 
x-rays or gamma rays, thus allowing more 
energy to pass through the material. Most 
discontinuities will appear as dark shapes 
on the radiographic film. 

e) The technique used for radiography de- 
pends largely on the equipment used and 
what experience has shown will produce 
the best results. It is not the function of the 
technician to indicate the procedure to be 
followed, provided the procedure and films 
satisfy all requirements of the applicable 
code of construction. The radiographic film 
provides a permanent record of the results 
of the examination. 



ing item or load-bearing structure. This method 
utilizes wave guides, transducers, cables, and a 
sophisticated data acquisition system to collect 
transient acoustic emissions generated by the 
rapid release of energy from localized sources 
within the material being tested. Signal ampli- 
tude, frequency, and location are collected for 
many hours of operation at various loads or 
pressures. Analysis of the data can determine 
if any part of the system requires additional 
nondestructive examination with a more sensi- 
tive test method. 



4.3 



TESTING METHODS 



All testing methods should be performed by ex- 
perienced personnel using written procedures 
acceptable to the Inspector. 



4.2.6 



EDDY CURRENT 



Eddy current is an examination method that 
measures changes in a magnetic field caused by 
discontinuities. Eddy current can also detect a 
loss of material on inaccessible surfaces and be 
used to detect changes in hardness of a mate- 
rial. There are three general types of eddy cur- 
rent coils: the concentric coil which surrounds 
the part to be tested (e.g., tubing); the probe 
coil which is brought adjacent to the part to be 
tested; and the bobbin coil which is inserted 
into the part to be tested (e.g., tubing). 



4.2.7 



METALLOGRAPHIC 



Metallographic examination is a method of 
locally polishing, etching, and viewing the 
surface of a pressure-retaining item with either 
acetate tape (e.g., replication) or a field micro- 
scope to determine the condition of the metal 
microstructure. 



4.2.8 



ACOUSTIC EMISSION 



Acoustic emission is a method of detecting and 
monitoring discontinuities in a pressure-retain- 



4.3.1 



PRESSURE TESTING 



b) 



During an inspection of a pressure-retain- 
ing item, there may be certain instances 
where inservice conditions have adversely 
affected the tightness of the component or 
the inspection discloses unusual, hard to 
eval uate forms of deterioration that may af- 
fect the safety of the vessel. In these specific 
instances, a pressure test using air, water, or 
other suitable test medium may be required 
at the discretion of the Inspector to assess 
leak tightness of the pressure-retaining 
item. 

The Inspector is cautioned that a pressure 
test will not provide any indication of the 
amount of remaining service life or the 
future reliability of a pressure-retaining 
item. The pressure test in this instance only 
serves to determine if the pressure-retaining 
item contains defects that wi 1 1 not al low the 
item to retain pressure. In certain instances, 
pressure tests of inservice components 
may reduce the remaining service life of 
the component due to causing permanent 
deformation of the item. 



7D 



NATIONAL BOARD INSPECTION CODE - PART 2 — INSPECTION 



c) If an inservice pressure test is required, the 
following precautions shall be met: 

1) The test pressure should not exceed 
90% of the set pressure of the lowest 
setting pressure relief device on the 
component to avoid damage to pres- 
sure relief devices. 

2) Test pressure should be selected or 
adjusted in agreement between the 
Inspector and the owner-user. When 
the original test pressure includes con- 
sideration of corrosion allowance, the 
test pressure may be further adjusted 
based upon the remaining corrosion 
allowance. 



4.3.2 



LEAK TESTING 



Leak testing for the purpose of detecting any 
leakage may be performed when a pressure 
test cannot be performed. Some methods or 
techniques for leak testing may include bubble 
test (direct pressure or vacuum), helium mass 
spectrometer, pressure change, or flow mea- 
surement. Use of leak test procedures shall be 
in agreement between the owner-user and the 
Inspector. Use of written procedures and expe- 
rienced personnel is required when performing 
leak tests. The Inspector shall review the written 
procedure to become familiar with limitations, 
adequacy, methods, and acceptance standards 
identified. 



3) The metal temperature during a pres- 4.3.3 
sure test should not be less than 60°F 
(1 6°C) unless the owner-user provides 
information on the toughness character- 
istics of the vessel material to indicate 
the acceptability of a lower test tem- 
perature. 



EVIDENCE OF LEAKAGE IN A 
BOILER 



4) The metal temperature shall not be 
more than 120°F (49°C) unless the 
owner-user specifies the requirement 
for a higher test temperature. If the 
owner-user specifies a test temperature 
higher than 1 20°F (49°C), then precau- b) 
tions shall be taken to afford the Inspec- 
tor close examination without risk of 
injury. 

5) When contamination of the vessel 
contents by any medium is prohibited 
or when a pressure test is not practical, 
other testing methods described below 
may be used provided the precaution- 
ary requirements of the applicable 
Section of the original construction 
code or other standards are followed. 
In such cases, there shall be agreement 
as to the testing procedure between the 
owner-user and the Inspector. 



For additional understanding regarding a leak 
in a boiler, see 2.2.7 for the extent of a pos- 
sible defect. A pressure test may be performed 
as follows: 

a) To determine tightness, the test pressure 
shall be no greater than the maximum al- 
lowable working pressure stamped on the 
pressure-retaining item. 



During a pressure test where the test pres- 
sure will exceed 90% of the set pressure of 
a pressure relief device, the device shall be 
removed whenever possible. If not possible 
or practical, a spindle restraint such as a 
gag may be used provided that the valve 
manufacturer's instructions and recom- 
mendations are followed. Extreme caution 
should be employed to ensure only enough 
force is applied to contain pressure. Exces- 
sive mechanical force applied to the spindle 
restraint may result in damage to the seat 
and/or spindle and may interfere with the 
proper operation of the valve. The spindle 
restraint shall be removed following the 
test. 



v i 



NATIONAL BOARD INSPECTION CODE • PART Z 



INSPECTION 



c) The organization who performs the pressure 
test and applies a spindle restraint shall 
attach a metal tag that identifies the orga- 
nization and date the work was performed 
to the pressure-relieving device. If the seal 
was broken, the organization shall reseal 
the adjustment housing with a seal that 
identifies the responsible organization. The 
process shall be acceptable to the Jurisdic- 
tion where the pressure-retaining items are 
installed. 

d) The temperature of the water used to ap- 
ply a pressure test should not be less than 
70°F (21 °C) and the maximum metal tem- 
perature during inspection shall not exceed 
120°F (49°C). A lower water temperature 
could be used if the owner can provide in- 
formation on the toughness characteristics 
of the material to indicate acceptability of 
the lower test temperature. 

e) Hold-time for the pressure test shall be 
for a minimum of 1 minutes prior to the 
examination by the Inspector. 

f) Hold-time for the examination by the 
Inspector shall be the time necessary for 
the Inspector to conduct the inspections. 
Test pressure shall be maintained until the 
hydrostatic test is completed. 

g) When the introduction of water for a pres- 
sure test will cause damage to a boiler or 
boiler component, other testing media or 
vacuum testing may be used provided the 
precautionary requirements of the appli- 
cable section of the original code of con- 
struction or other standards are followed. 
In such cases, there shall be agreement as 
to the testing procedure between the owner 
and the Inspector. 



4.4 



4.4.1 



METHODS TO ASSESS DAMAGE 
MECHANISMS AND 
INSPECTION FREQUENCY FOR 
PRESSURE-RETAINING ITEMS 



SCOPE 



a) This section provides guidelines and al- 
ternative methods to assess materials and 
pressure-retaining items subject to degrada- 
tion or containing flaws identified during 
inservice inspections or examinations. 
New pressure-retaining items are placed 
in service to operate within their intended 
design parameters for a period of time de- 
termined by service conditions, which can 
include exposure to corrosion, exposure to 
elevated temperature (creep), or other forms 
of damage. If the pressure-retaining item 
is to remain safe in operation, the service 
conditions and the length of time before the 
next inspection must be identified. There 
are various methods that can be used to 
assess the condition of a pressure-retain- 
ing item to establish remaining service life 
and to ultimately determine the inspection 
interval. In some cases, a visual inspection 
of the pressure-retaining item will suffice. 
However, more comprehensive condition 
assessment methods may be required, 
including an engineering evaluation per- 
formed by a competent technical source 
(see 5.3.2). 

b) Various assessment methods (See 1.3), 
including those mentioned in this Section 
(an example of guidelines for performing 
fitness for service assessments are refer- 
enced in API recommended practice API- 
579 "Fitness-for-Service"), can be used to 
establish the next inspection interval of a 
pressure-retaining item and to assure safe 
operation. Condition assessment methods 
shall be subject to review and acceptance 
by the Jurisdiction. 



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NATIONAL BDARD INSPECTION CODE • PART 2 — INSPECTION 



c) Safe and adequate implementation of 
Fitness for Service Assessment (FFSA) pro- 
grams is the responsibility of the owner- 
user. Responsibility includes verifying and 
understanding jurisdictional rules/regula- 
tions and inservice inspection require- 
ments. Application of these programs may 
result in decisions that will deviate from or 
conflict with jurisdictional requirements 
(i.e. frequency or types of inspections, 
repairs and alterations, etc.). The Inspector 
or Jurisdiction shall be contacted for accep- 
tance, as appropriate, prior to implement- 
ing decisions that deviate from or conflict 
with established requirements. 

d) If required by the Jurisdiction, FFSA shall be 
documented on a Report of FFSA as shown 
in 5.3.7. Preparation of the Report of FFSA 
shall be the responsibility of the owner-user. 
An Inspector shall indicate acceptance by 
signing the Report of FFSA. Legible copies 
of the FFSA report shall be distributed to 
thejurisdiction, and the Authorized Inspec- 
tion Agency responsible for the inservice 
inspection. The owner-user shall maintain 
a copy of the FFSA report in the relevant 
equipment inspection history file. 



b) There are various condition assessment 
and fitness for service methods that can 
be used to determine inspection intervals, 
based on calculating the remaining service 
life of the pressure-retaining item. For items 
subject to corrosion or erosion, the method 
to determine or adjust inspection intervals 
is identified in 4.4.7. Methods for assessing 
other types of inservice damage that affect 
remaining service life of pressure-retaining 
items are identified in 4.4.8. 



4.4.3 



RESPONSIBILITIES 



a) Owner-User 

The owner-user of the pressure-retaining 
item is responsible for the selection and 
application of a suitable fitness for service 
or condition assessment methodology 
described in this section, subject to re- 
view and approval by the Jurisdiction, if 
required. 

b) Inspector 

The Inspector shall review the condition 
assessment methodology and assure in- 
spection data and documentation are in 
accordance with this section. 



4.4.2 



GENERAL REQUIREMENTS 



a) Organizations or qualified individuals with 
experience in inspection, design, construc- 
tion, repairs, or failure analysis of pressure- 
retaining items should be consulted to assist 
in identifying damage mechanisms, and 
to evaluate condition assessment results 
of pressure-retaining items. Documenta- 
tion and inspection data used for fitness 
for service assessment should be evalu- 
ated for compliance, with codes, industry 
standards/experience or good engineering 
practices, and shall be acceptable to the 
Jurisdiction. Understanding the operation 
of equipment or systems and interaction 
with their internal or external service en- 
vironment is necessary to correctly identify 
damage mechanisms. 



4.4.4 REMAINING SERVICE LIFE 

ASSESSMENT METHODOLOGY 

a) An evaluation of inservice damage using 
one or more condition assessment methods 
is not intended to provide a precise deter- 
mination of the actual time to failure for a 
pressure-retaining item. Instead, the extent 
of inservice damage should be estimated 
based on the quality of available informa- 
tion, established engineering assessment 
guidelines or methodology and appropriate 
assumptions used for safety, operation, and 
inspection. 

b) If inspection and engineering assessment 
results indicate that a pressure-retaining 
item is safe for continued operation, fu- 



73 



NATIONAL BOARD INSPECTION CODE • PART Z 



INSPECTION 



ture monitoring and inspection intervals 
should be determined and submitted to 
the Jurisdiction for review and approval. If 
an engineering assessment indicates that 
a pressure-retaining item is not suitable 
for service under current operating condi- 
tions, new operating conditions should be 
established (i.e., de-rate), or the item could 
be repaired subject to revised inspection 
intervals, or the item could be replaced. 

c) Determination of the extent of inservice 
damage life requires the following: 

1 ) Understanding applicable damage and 
failure mechanisms; 

2) Developing inspection plans that can 
monitor the extent of inservice dam- 
age; 

3) Performing an assessment of the dam- 
age including estimation of remaining 

life; 

4) Considerations needed to minimize risk 
of failure; 

5) Determination of root cause; and 

6) Corrective measures. 



4.4.5 DATA REQUIREMENTS FOR 

REMAINING SERVICE LIFE 
ASSESSMENTS 

Evaluating the extent of inservice damage to a 
pressure-retaining item requires an understand- 
ing of known and potential damage mecha- 
nisms. Information that can be used to evaluate 
service life can be divided into three categories: 
inspection history, operating and maintenance 
history, and equipment information. Examples 
of types of data are listed below: 

a) Inspection History 

1 ) Summary/records of Repairs and Altera- 
tions; 



2) Test Records including pressure tests; 

3) Results of prior inservice examinations 
(NDE methods, thickness measure- 
ments, and corrosion rate); and 

4) Physical measurements or inspec- 
tions. 

b) Operating History/Conditions 

1) Operating logs to include pressure, 
temperature, startups/shutdowns, 
cycles; 

2) Consult with operating personnel to 
determine operating history; 

3) Date of installation; 

4) Identify internal and external environ- 
mental conditions to include pressure, 
temperature, age, design, chemical and 
mechanical environment, loadings, 
processes, etc.; 

5) List damage mechanisms identified in 
the past and that may be present based 
on materials, contaminants, and operat- 
ing conditions; 

6) Identify the damage mechanisms pres- 
ently active or which may become ac- 
tive; and 

7) Identify the failure modes associated 
with the identified damage mecha- 
nisms, i.e., leaks, cracks, bursts, etc. 

c) Equipment Information 

1) Manufacturer's Data Reports 

2) Material Test Reports 

3) Drawings 

4) Original design calculations/specifica- 
tions 



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INSPECTION 



4.4.6 IDENTIFICATION OF DAMAGE 

MECHANISMS 

a) There are a variety of damage mechanisms 
that may affect the remaining service life 
of a pressure-retaining item. Damage 
mechanisms will cause either micro or 
macro changes to the material affecting its 
conditions or properties. Damage mecha- 
nisms may be difficult to assess, therefore, 
detailed methods of evaluation for each 
damage mechanism should be performed 
in accordance with established industry 
practices or other acceptable standards 
should be followed (See 1 .3). These results 
should be evaluated and the inspection 
interval reviewed for possible adjustment. 
Various failure modes are described in Sec- 
tion 3 of this Part. 

b) Common forms of damage and damage 
mechanisms that affect remaining service 
life evaluations are listed below: 

1) Bulging 

2) Sagging 

3) Stress corrosion cracking 

4) Corrosion (local or general) 

5) Creep 

6) Thermal or mechanical fatigue 

7) Hydrogen damage 

8) Metallurgical changes 

9) Erosion 

c) Damage may also be caused by mechani- 
cal forces such as thermal shock, cyclic 
temperature changes, vibration, pressure 
surges, excessive temperature, external 
loading, material and fabrication defects. 



4.4.7 DETERMINING INSPECTION 

INTERVALS 

a) The maximum period between internal 
inspections or a complete inservice evalu- 
ation of pressure-retaining items shall not 
exceed one-half of the estimated remain- 
ing service life of the vessel or ten years, 
whichever is less. The method for estimating 
inspection intervals of pressure-retaining 
items subject to internal erosion or corro- 
sion is discussed in 4.4.7.1 and 4.4.7.2. 

b) Inspection intervals can be revised beyond 
the maximum period stated above, pro- 
vided the owner-user has submitted techni- 
cal justification for revising the inspection 
interval, subject to review and acceptance 
by the Jurisdiction, where required. 

c) Data used in engineering assessment meth- 
ods to develop revised inspection intervals 
for pressure-retaining items shall be re- 
evaluated every five years, when a change 
in operation occurs, or after discovery of 
new and/or altered damage mechanisms. 



4.4.7.1 METHOD FOR ESTIMATING 
INSPECTION INTERVALS FOR 
PRESSURE-RETAINING ITEMS 
SUBJECT TO EROSION OR 
CORROSION 

Assessment guidelines for pressure-retain- 
ing items subject to corrosion or erosion are 
provided in this section. These guidelines are 
based on actual thickness measurements within 
the area of concern. Minimum required wall 
thickness shall be based on allowable stress of 
the material. Applicability and limitations of 
this guideline are as follows: 

a) Original design criteria is known; 

b) Item is not operating in the creep range; 

c) Item does not contain crack-like indica- 
tions; 



75 



NATIONAL BOARD INSPECTION CODE • PART Z 



INSPECTION 



d) Service stresses are known; and 

e) Maintenance and operating history are 
known. 



4.4.7.2 METHOD FOR ESTIMATING 
INSPECTION INTERVALS FOR 
EXPOSURE TO CORROSION 

a) When the pressure-retaining item is ex- 
posed to service temperatures below the 
creep range, and the corrosion rate controls 
the remaining wall thickness of the pres- 
sure-retaining item, the inspection interval 
shall be calculated by the formula below 
or by other industry methods as accepted 
by the Jurisdiction. 



remaining life 
(years) 



- t, . ,. / corrosion 

(required) 

rate 



Actual) = thickness in inches (mm) measured 
at the time of inspection for the limit- 
ing section used in the determination 

of t, ... 

(required) 

t, . ,. = minimum allowable thickness in 

(required) 

inches (mm) for the limiting section of 
the pressure-retaining item or zone. It 
shall be the greater of the following: 

1) The calculated thickness, exclusive of 
the corrosion allowance, required for 
the pressure relieving device set pres- 
sure, static head, or other loading and 
design temperature, or 

2) The minimum thickness permitted by 
the provision of the applicable Section 
of the original code of construction. 

Corrosion Rate = inches (mm) per year 
of metal removal as a result of corro- 
sion. 

b) Any suitable nondestructive examination 
method may be used to obtain thickness 
measurements provided the instruments 



employed are calibrated in accordance 
with the manufacturer's specification or an 
acceptable national standard. 

1) If suitably located existing openings are 
available; measurements may be taken 
through the openings. 

2) When it is impossible to determine 
thickness by nondestructive means, a 
hole may be drilled through the metal 
wall and thickness gage measurements 
taken. 

c) For new pressure-retaining items or PRI's 
for which service conditions are being 
changed, one of the following methods 
shall be employed to determine the prob- 
able rate of corrosion from which the re- 
maining wall thickness, at the time of the 
next inspection, can be estimated: 

1) The corrosion rate as established by 
data for pressure-retaining items in the 
same or similar service; 

2) If the probable corrosion rate cannot be 
determined by the above method, on- 
stream thickness determinations shall 
be made after approximately 1,000 
hours of service. Subsequent sets of 
thickness measurements shall be taken 
after additional similar intervals until 
the corrosion rate is established. 

d) Corrosion Resistant Lining 

When part or all of the pressure-retain- 
ing items has a corrosion resistant lining, 
the interval between inspections of those 
sections so protected may be based on 
recorded experience with the same type 
of lining in similar service, but shall not 
exceed ten years, unless sufficient data has 
been provided to establish an alternative 
inspection interval. If there is no experi- 
ence on which to base the interval between 
inspections, performance of the liner shall 
be monitored by a suitable means, such as 
the use of removable corrosion probes of 



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NATIONAL BOARD INSPECTION CODE - PART 2 



INSPECTION 



the same material as the lining, ultrasonic 
examination, or radiography. To check 
the effectiveness of an internal insulation 
liner, metal temperatures may be obtained 
by surveying the pressure-retaining item 
with temperature measuring or indicating 
devices. 

e) Two or More Zones 

When a pressure-retaining item has two or 
more zones of pressure or temperature and 
the required thickness, corrosion allow- 
ance, or corrosion rate differ so much that 
the foregoing provisions give significant 
differences in maximum periods between 
inspections for the respective zones (e.g., 
the upper and lower portions of some 
fractionating towers), the period between 
inspections may be established individually 
for each zone on the basis of the condi- 
tion applicable thereto, instead of being 
established for the entire vessel on the basis 
of the zone requiring the more frequent 
inspection. 

f) Above-Ground Pressure Vessels 

All pressure vessels above ground shall 
be given an external examination after 
operating the lesser of five years, or one 
quarter of remaining life, preferably while 
in operation. Alternative intervals resulting 
in longer periods may be assigned pro- 
vided the requirements of this section have 
been followed. Inspection shall include 
determining the condition of the exterior 
insulation, the supports, and the general 
alignment of the vessel on its supports. 
Pressure vessels that are known to have a 
remaining life of over ten years or that are 
prevented from being exposed to external 
corrosion (such as being installed in a cold 
box in which the atmosphere is purged with 
an inert gas, or by the temperature being 
maintained sufficiently low or sufficiently 
high to preclude the presence of water), 
need not have the insulation removed for 
the external inspection. However, the con- 
dition of the insulating system and/or the 
outer jacketing, such as the cold box shell, 



shall be observed periodically and repaired 
if necessary. 

g) Interrupted Service 

1) The periods for inspection referred to 
above assume that the pressure- retain- 
ing item is in continuous operation, 
interrupted only by normal shutdown 
intervals. If a pressure-retaining item is 
out of service for an extended interval, 
the effect of the environmental condi- 
tions during such an interval shall be 
considered. 

2) If the pressure-retaining item was 
improperly stored, exposed to a detri- 
mental environment or the condition is 
suspect, it shall be given an inspection 
before being placed into service. 

3) The date of next inspection, which was 
established at the previous inspection, 
shall be revised if damage occurred dur- 
ing the period of interrupted service. 

h) Circumferential Stresses 

For an area affected by a general corrosion 
in which the circumferential stresses govern 
the MAWP, the least thicknesses along the 
most critical plane of such area may be 
averaged over a length not exceeding: 

1 ) The lesser of one-half the pressure ves- 
sel diameter, or 20 in. (500 mm) for 
vessels with inside diameters of 60 in. 
(1 .5 m) or less, or 

2) The lesser of one-third the pressure ves- 
sel diameter, or 40 in. (1 m), for vessels 
with inside diameters greater than 60 in. 
(1.5 m), except that if the area contains 
an opening, the distance within which 
thicknesses may be averaged on either 
side of such opening shall not extend 
beyond the limits of reinforcement as 
defined in the applicable Section of the 
ASME Code for ASME Stamped vessels 
and for other vessels in their applicable 
codes of construction. 



vv 



NATIONAL BOARD INSPECTION CODE ° PART Z 



INSPECTION 



k) 



Longitudinal Stresses 

If because of wind loads or other factors 
the longitudinal stresses would be of im- 
portance, the least thicknesses in a length 
of arc in the most critical plane perpen- 
dicular to the axis of the pressure vessel 
may be averaged for computation of the 
longitudinal stresses. The thicknesses used 
for determining corrosion rates at the re- 
spective locations shall be the most critical 
value of average thickness. The potential for 
buckling shall also be considered. 

Local Metal Loss 

Corrosion pitting shall be evaluated in ac- 
cordance with 5.3.8.7. Widely scattered 
corrosion pits may be left in the pressure- 
retaining item in accordance with the fol- 
lowing requirements: 

1) Their depth is not more than one-half 
the required thickness of the pressure- 
retaining item wall (exclusive of corro- 
sion allowance); 

2) the total area of the pits does not exceed 
7 sq. in. (4500 sq mm) within any 50 
sq. inches (32000 sq mm); and 

3) the sum of their dimensions (depth and 
width) along any straight line within this 
area does not exceed 2 in. (50 mm). 

Weld Joint Efficiency Factor 
When the surface at a weld having a joint 
efficiency factor of other than one is cor- 
roded as well as surfaces remote from the 
weld, an independent calculation using 
the appropriate weld joint efficiency factor 
shall be made to determine if the thickness 
at the weld or remote from the weld governs 
the maximum allowable working pressure. 
For the purpose of this calculation, the 
surface at a weld includes 1 in. (25 mm) 
on either side of the weld, or two times the 
minimum thickness on either side of the 
weld, whichever is greater. 



I) Formed Heads 

1 ) When evaluating the remaining service 
life for ellipsoidal, hemispherical, tori- 
spherical or toriconical shaped heads, 
the minimum thickness may be calcu- 
lated by: 

a. Formulas used in original construc- 
tion, or 

b. Where the head contains more than 
one radii of curvature, the appro- 
priate strength formula for a given 
radius. 

2) When either integral or non-integral at- 
tachments exist in the area of a knuckle 
radius, the fatigue and strain effects that 
these attachments create shall also be 
considered. 

m) Adjustments in Corrosion Rate 

If, upon measuring the wall thickness at any 
inspection, it is found that an inaccurate 
rate of corrosion has been assumed, the 
corrosion rate to be used for determining 
the inspection frequency shall be adjusted 
to conform with the actual rate found. 

n) Riveted Construction 

For a pressure-retaining item with riveted 
joints, in which the strength of one or more 
of the joints is a governing factor in estab- 
lishing the maximum allowable working 
pressure, consideration shall be given as 
to whether and to what extent corrosion 
will change the possible modes of failure 
through such joints. Also, even though no 
additional thickness may have originally 
been provided for corrosion allowance 
at such joints, credit may be taken for the 
corrosion allowance inherent in the joint 
design. 



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INSPECTION 



4.4.7.3 ESTIMATING INSPECTION 
INTERVALS FOR PRESSURE- 
RETAINING STEMS WHERE 
CORROSION IS NOT A FACTOR 

When the corrosion rate of a pressure-retaining 
item is not measurable, the item need not be 
inspected internally provided all of the follow- 
ing conditions are met and complete external 
inspections, including thickness measurements, 
are made periodically on the vessel. 

a) The non-corrosive character of the content, 
including the effect of trace elements, has 
been established by at least five years com- 
parable service experience with the fluid 
being handled. 

b) No questionable condition is disclosed by 
external inspection. 

c) The operating temperature of the pressure- 
retaining item does not exceed the lower 
limits for the creep range of the vessel 
metal. Refer to Table 4.4.8.1 . 

d) The pressure-retaining item is protected 
against inadvertent contamination. 



4.4.8 EVALUATING INSPECTION 

INTERVALS OF PRESSURE- 
RETAINING ITEMS EXPOSED TO 
INSERVICE FAILURE 
MECHANISMS 

Pressure-retaining items are subject to a variety 
of inservice failure mechanisms that are not 
associated with corrosion. The following pro- 
vides a summary of evaluation processes that 
may require a technical evaluation to assess 
resultant inspection intervals. 



4.4.8.1 EXPOSURE TO ELEVATED 

TEMPERATURE (CREEP) 

a) The owner-user of the pressure-retaining 
item and the Inspector are cautioned to 



seek competent technical advice to deter- 
mine which of the condition assessment 
methods can be used to assure safe opera- 
tion and determination of the next inspec- 
tion interval for the pressure-retaining item 
when elevated service temperature is a 
consideration. 

b) When creep damage is suspected in a 
pressure-retaining item, an assessment of 
remaining service life should be determined 
either by the owner-user of the pressure-re- 
taining item or a competent engineer. This 
assessment may include, but is not limited 
to, the following methods: 

1 ) Dimensional measurements of the item 
to check for creep. 

2) Measurement of oxide scale and wall 
thickness for use in engineering analy- 
sis to determine remaining service life. 
Creep life can be predicted through an 
empirical approach that uses available 
data for the pressure-retaining compo- 
nent; total number of operating hours 
to the present is needed. Oxide scale 
thickness (steam side) can be measured 
directly from material samples or be 
measured in situ using ultrasonic tech- 
niques. 



TABLE 4.4.8.1 -Temperatures Above 
Which Creep Becomes a Consideration 



Carbon Steel and C-1/2 
Mo and Ferritic 
Stainless Steels 


750°F (400°C) 


Low Alloy Steels 
(Cr-Mo) 


850°F(455°C) 


Austenitic Stainless 
Steel 


950°F(510°C) 


Aluminum Alloys 


200°F (93°C) 



Metal lographic examination to deter- 
mine the extent of exposure to creep 
damage. 



79 



NATIONAL BOARD INSPECTION CODE • PART 2 



INSPECTION 



4) After removal of a material sample for 
creep rupture testing, a test matrix is 
selected to yield the most meaningful 
results from the sample. Test speci- 
mens are machined from the sample 
and tested under representative loads 
and temperatures (as selected in the 
test matrix). Creep strain vs. time and 
temperature vs. time to rupture data are 
recorded. 



4.4.8.2 EXPOSURE TO BRITTLE 
FRACTURE 

a) Determining susceptibility to brittle fracture 
should be required as part of the overall as- 
sessment for evaluating remaining service 
life or to avoid failure of the pressure-retain- 
ing item during a pressure test. In order to 
carry out brittle fracture assessment, me- 
chanical design information, materials of 
construction and materials properties are to 
be determined. This information is required 
for pressure-retaining components in order 
to identify the most limiting component ma- 
terial that governs brittle fracture. Design in- 
formation, maintenance/operating history, 
and information relating to environmental 
exposure shall be evaluated to determine 
if there is a risk of brittle fracture. 

b) When brittle fracture is a concern, methods 
to prevent this failure shall be taken. These 
methods could include changes to oper- 
ating conditions and further engineering 
evaluations to be performed by a qualified 
engineer (metallurgical/corrosion/mechani- 
cal). Engineering evaluation methods to 
prevent brittle fracture shall be reviewed 
and accepted by the owner-user, Inspector, 
and Jurisdiction, as required. 



4.4.8.3 EVALUATING CONDITIONS 

THAT CAUSE BULGES/BLISTERS/ 
LAMINATIONS 

a) Blistering in pressure-retaining items can 
result from laminations, inclusions in the 



metal, or damage mechanisms that oc- 
cur in service. Procedures for evaluating 
bulges/blisters/laminations are referenced 
in applicable standards (see 1 .3). 

b) An engineering evaluation shall be per- 
formed to ensure continued safe operation 
when bulges/blisters/laminations are identi- 
fied. If a bulge/blister/lamination is within 
the specified corrosion allowance, further 
assessment shall be performed to evaluate 
any crack-like indications in surrounding 
base material. 

Note: Proximity of crack-like indications in 
welds and HAZ is important. Cracks and 
blisters should be evaluated separately. 



4.4.8.4 EVALUATING CRACK-LIKE 

INDICATIONS IN PRESSURE- 
RETAINING ITEMS 

a) Crack-like indications in pressure-retaining 
items are planar flaws characterized by 
length and depth with a sharp root radius. 
Cracks may occur within material or on the 
surface and may be individual or multiple 
in nature. In some cases, a conservative 
approach is to treat aligned porosity, inclu- 
sions, undercuts, and overlaps as crack-like 
indications. It is important that the cause 
of cracking is identified prior to any further 
determination of inspection intervals. 

b) If crack-like indications are on the surface 
and within the specified corrosion allow- 
ance, removal by blend grinding or air arc 
gouging can be performed. Measurements 
shall betaken to assure minimum thickness 
is met and effective monitoring techniques 
should be established. If a crack-like flaw 
is not completely removed and repaired, 
then an engineering fracture mechanics 
or other evaluation must be performed to 
verify continued safe operation. 

c) There are various methods or approaches 
for evaluating crack-like indications, some 
of which are referenced in applicable stan- 
dards (see 1 .3). 



so 



NATIONAL BOARD INSPECTION CODE • PART 2 — INSPECTION 



4.4.8.5 EVALUATING EXPOSURE OF A 

PRESSURE-RETAINING ITEM TO 
FIRE DAMAGE 

a) The extreme heat of a fire can produce 
visual structural damage and less apparent 
degradation of mechanical properties (de- 
crease in yield strength or fracture tough- 
ness). Potential damage includes changes in 
mechanical properties, decrease in corro- 
sion resistance, distortion, and cracking of 
pressure boundary components. Distortion 
of equipment extremities such asladders 
and platforms does not necessarily mean 
that the pressure equipment is no longer 
suitable for continued service. Process 
fluid inside the vessel may serve as a cool- 
ing medium, thus preserving mechanical 
properties of the equipment. Instrumenta- 
tion and wiring are commonly damaged 
during a fire. Data requirements and history 
information should be obtained as identi- 
fied in 4.4.5. 

b) Recommended measurements and collec- 
tion of data for evaluation of fire damage 
shall include but are not limited to: 

1 ) Concentrated areas of fire damage ver- 
sus overall fire damage as it relates to 
normal operation 

2) Determination of cause and origin of 
fire 

3) Temperature extremes 

4) Nature of the fuel 

5) Source of ignition 

6) Time at temperature 

7) Cooling rate 

8) Photographs taken 



9) Plant personnel interviewed 

10) Actual strength and toughness proper- 
ties of the material 

Note: It is important that evidence be 
maintained in order to perform a proper 
evaluation. 

c) Components subjected to fire damage can 
exhibit altered mechanical properties, and 
should be evaluated to determine if the 
material has retained necessary strength 
and toughness as specified in the original 
code of construction. Heating above the 
lower critical temperature results in a phase 
transformation that upon rapid cooling can 
dramatically affect material properties. 
Evaluation methods may consist of: 

1 ) Portable hardness testing 

2) Field metallography or replication 

3) Pressure testing 

4) Magnetic particle testing 

5) Liquid penetrant testing 

6) Visual examination 

7) Dimensional verification checks 

d) If visual distortion or changes in the mi- 
crostructure or mechanical properties are 
noted, consider replacing the component 
or a detailed engineering analysis shall be 
performed to verify continued safe opera- 
tion. 

e) Techniques for evaluating fire damage are 
referenced in applicable standards. See 
1.3. 



s i 



NATIDNAL BDARD INSPECTION CODE • PART 2 — INSPECTION 



4.4.8.6 EVALUATING EXPOSURE OF 
PRESSURE-RETAINING ITEMS 
TO CYCLIC FATIGUE 

a) A fatigue evaluation should be performed 
if a component is subject to cyclic op- 
eration. The allowable number of cycles 
(mechanical or thermal) at a given level of 
stress should be adequate for the specified 
duration of service to determine suitability 
for continued operation. 

b) Data requirements and history information 
should be obtained as identified in 4.4.5. 

c) Techniques for evaluating fatigue are refer- 
enced in applicable standards. See 1 .3. 



4.4.8.7 EVALUATING PRESSURE- 
RETAINING ITEMS 
CONTAINING LOCAL THIN 
AREAS 

a) Local thin areas can result from corro- 
sion/erosion, mechanical damage, or 
blend/grind techniques during fabrication 
or repair, and may occur internally or exter- 
nally. Types of local thin areas are grooves, 
gouges, and pitting. When evaluating these 
types of flaws, the following should be 
considered: 

1) Original design and current operating 
conditions 

2) Component is not operating in the 
creep range 

3) Material has sufficient toughness 

4) Not operating in cyclic service 

5) Does not contain crack-like indica- 
tions 

6) Flaws are not located in knuckle regions 
of heads or conical transitions 



7) Applied loads 

8) The range of temperature or pressure 
fluctuation 

b) Where appropriate, crack-like indications 
should be removed by blend/grinding, and 
evaluated as a local thin area. 

c) Data requirements and history information 
should be obtained as identified in 4.4.5. 

d) Required measurements for evaluation of 
local thin areas shall include: 

1 ) Thickness profiles within the local 
region 

2) Flaw dimensions 

3) Flaw to major structural discontinuity 
spacing 

4) Vessel geometry 

5) Material properties 

e) Required measurements for evaluation of 
pitting corrosion shall include: 

1) Depth of the pit 

2) Diameter of the pit 

3) Shape of the pit 

4) Uniformity 

f) If metal loss is less than specified corrosion/ 
erosion allowance and adequate thickness 
is available for future corrosion, then moni- 
toring techniques should be established. If 
metal loss is greater than specified corro- 
sion/erosion allowance and repairs are not 
performed, a detailed engineering evalua- 
tion shall be performed to ensure continued 
safe operation. 



82 



NATIONAL BOARD INSPECTION CDDE • PART 2 



INSPECTION 



g) Techniques for evaluating local thin areas 
and pitting are referenced in applicable 
standards. See 1 .3. 



4.5.2 



DEFINITIONS 



4.5 



4.5.1 



RISK-BASED INSPECTION 
ASSESSMENT PROGRAMS 



SCOPE 



b) 



This section describes the basic elements, 
principles, and guidelines of a risk based 
inspection (RBI) program. This section 
does not address any one method but is 
intended to clarify the elements associated 
with a RBI program. Risk assessment is a 
process to evaluate continued safe opera- 
tion of a pressure-containing component. 
This process is based on sound engineering 
practices, proven risk assessment experi- 
ence and management principles. There are 
numerous risk-based assessment methods 
being applied throughout many industries. 
Details for developing and implementing 
risk-based inspection programs are defined 
in other referenced standard. 

Implementation of a risk-based inspection 
(RBI) assessment program allows an owner- 
user to plan inspection frequencies based 
on assessing probability of failure (POF) and 
consequence of failure (COF) (risk = POF x 
COF). Risk assessment programs involve a 
team concept based on knowledge, train- 
ing and experience between engineers, 
inspectors, operators, analysts, financial, 
maintenance, and management personnel. 
Appropriate and responsible decisions must 
be made from input by all team members to 
assure safe operation of systems and their 
components. Organizational commitment 
and cooperation is required to successfully 
implement and maintain a RBI program. 



COF — Consequence of Failure. Outcome from 
a failure. There may be one or more outcomes 
from a single failure. 

POF — Probability of Failure. Extent to which 
a failure is likely to occur within a specific 
time frame. 

Risk — a combination of probability of an event 
occurring and the consequences associated 
with the event. Risk = (POF x COF). 

Risk Assessment — A process of risk analysis 
and evaluation. 

Risk Analysis — Identification and use of infor- 
mation such as historical data, opinions, and 
concerns to evaluate, treat, and accept risk. 

Risk-Based Inspection — Inspection managed 
through risk assessment. 

Risk Criteria — Terms used whereby the signifi- 
cance of risk is assessed, such as personnel safe- 
ty, cost benefits, legal/statutory requirements, 
economic/environmental aspects, stakeholders 
concerns, priorities, etc. 

Risk Evaluation — Process to compare risk with 
given criteria to determine the significance 
of risk to assist in accepting or mitigating the 
risk. 

Uncertainty — A measure of confidence in the 
expected value. 



4.5.3 



GENERAL 



Risk-based inspection assessment programs 
can provide the following benefits for organi- 
zations: 

a) An overall reduction in risk of equipment 
failure; 



S3 



NATIONAL BOARD INSPECTION CODE • PART 2 



INSPECTION 



b) Identification of items not requiring inspec- 
tion or mitigation; 

c) An acceptable understanding of the cur- 
rent risk for specific items under consider- 
ation; 

d) Process safety improvements; by concen- 
trating inspections, maintenance and as- 
sociated expenditures on items of high risk 
and reducing efforts on low risk items; 

e) Improved record retention for items by re- 
taining both historical and latest essential 
data and information needed for assess- 
ment; 

f) Provides a management tool to continu- 
ally: 

1) maintain an effective inspection and 
maintenance program; 

2) improve reliability and safety for opera- 
tion; 

3) define staffing needs; 

4) evaluate and define funds required; 

5) adjusts risk assessment program based 
on desired results; and 

6) Manage uncertainty. 



4.5.4 



CONSIDERATIONS 



Effective risk-based inspection programs should 
consider the following: 

a) Significance of failure on personnel safety; 

b) Identifying and obtaining accurate and 
appropriate information on system or com- 
ponent; 

c) Using appropriate inspection methods and 
types (internal, external, inservice, etc) fre- 
quencies, and understanding limitations; 



d) Design requirements; 

e) Installation requirements; 

f) Operational requirements and limitations; 

g) Proper execution of plans; 

h) Qualifications and training requirements 
for personnel; 

i) Use and development of procedures; 

j) Sound engineering and operating judg- 
ment; 

k) Effective communication among all affected 
areas of management and personnel; 

I) Jurisdictional and Inspector involvement as 
required; 

m) Human error; 

n) Consequential and secondary effects; and 

o) Impact of failure on personnel or opera- 
tions. 



4.5.5 KEY ELEMENTS OF AN RBI 

ASSESSMENT PROGRAM 

The following key elements should be included 
when establishing an RBI program: 

a) Establish objectives and goals; 

b) Understand risk of operation by identifying 
effects of inspection, maintenance, operat- 
ing parameters, and mitigating actions; 

c) Defining roles, responsibilities, training, 
and qualifications; 

d) Define risk criteria; 

e) Managed actions for acceptable levels of 
risk; 



34 



NATIONAL BOARD INSPECTION CODE • PART Z 



INSPECTION 



f) Understanding and meeting safety and 
environmental requirements; 

g) Optimizing expenditures; 

h) Assessing mitigation alternatives; 

i) Data and information collection; 

j) Identifying deterioration mechanisms (see 
Section 3 of this Part); 

k) Assessing POF and COF; 

I) Determine an acceptable risk matrix; 

m) Reassessing and updating RBI assessments; 
and 

n) Required documentation and retention. 



4.5.6 



RBI ASSESSMENT 



Assessments provide a systematic approach to 
screen risk, identify areas of concern, and de- 
velop a list for needed inspections or analysis. 
Probability of failure (POF) and consequence of 
failure (COF) must first be evaluated separately. 
Risk is then determined as, (POF x COF) to de- 
velop a risk ranking measure or estimate. 



4.5.6.1 



PROBABILITY OF FAILURE 



Probability of failure can be expressed in terms 
of number of events occurring during a specific 
time frame. There are three main considerations 
when analyzing POF. 

a) Evaluate deterioration mechanisms based 
on materials and the item's operating envi- 
ronment. 

b) Evaluate the impact of deterioration mecha- 
nisms on the integrity of the PRI(s). 

c) Determine the effectiveness of the inspec- 
tion program to quantify and monitor dete- 



rioration mechanisms either on or off-line, 
so that mitigation can be effective prior to 
failure. 



4.5.6.2 CONSEQUENCE OF FAILURE 

Consequence analysis involves logic modeling 
to depict combinations of events to represent 
effects of failure. These models usually contain 
one or more failure scenarios. Consequence 
categories for consideration include the fol- 
lowing: 

a) Personnel safety; 

b) Business/production effects including cost 
related to down time or collateral damage 
to surrounding equipment; 

c) Affected area; 

d) Environmental damage; 

e). Volume of fluid or gas released; 

f) Toxic or flammable events; and 

g) Maintenance/repairs/replacement. 

4.5.6.3 RISK EVALUATION 

Once POF and COF are assessed and assigned, 
categories of risk can be calculated and evalu- 
ated. A risk matrix or plot is helpful to display 
or present risk without using numerical values 
with categories such as low, medium, and high 
typically assigned to identify POF and COF. 
POF and COF categories can be presented eas- 
ily to understand and manage risk. Using the 
risk evaluation, an inspection plan, including 
proposed inspection frequencies and appro- 
priate inspection methods is developed and 
implemented. 



B5 



NATIONAL BOARD INSPECTION CODE • PART 2 — INSPECTION 

4.5.6.4 RISK MANAGEMENT 

Based on risk ranking and identifying accept- 
able thresholds, risk management or mitigation 
can proceed. When risk is considered unac- 
ceptable, the following action should be taken 
to minimize POF or COR These may include 
but are not limited to the following: 

a) Decommissioning; 

b) Increased monitoring/inspection; 

c) Repair/Replace/maintain; 

d) De-rate equipment — needs/limits/cycles; 

e) Modifications/redesign; 

f) Training; and 

g) Enhance process control. 



4.5.7 JURISDICTIONAL 

RELATIONSHIPS 

Jurisdictions mandate specific Codes/Standards 
with rules or laws that may differ between ju- 
risdictions. Frequency and types of inspections 
are examples of requirements that may vary. 
Owners and users implementing RBI assess- 
ment plans should understand jurisdictional 
requirements, so deviations from the mandated 
types of inspection and frequency of inspection 
can be requested. Methods used to develop and 
implement RBI assessment methods and the 
RBI program developed from those methods 
shall be acceptable to the jurisdiction and the 
inspector as required. 



se 



Insert 

Section 5 
Tab 

Here 




Part 2, Section 5 
Inspection — Stamping, 
Documentation, and Forms 



87 



NATIONAL BOARD INSPECTION CODE • PART 2 



INSPECTION 



PART 2, SECTION 5 

INSPECTION — STAMPING, 

DOCUMENTATION, AND FORMS 



5.1 



SCOPE 



This section provides guidelines and require- 
ments for stamping and documentation (Forms) 
for inservice inspections of PRIs. This section 
also describes evaluation of inspection results 
and assessment methodologies. 



5.2 REPLACEMENT OF STAMPING 

DURING INSERVICE 
INSPECTION 



5.2.2 REPLACEMENT OF 

STAMPED DATA 

a) The re-stamping or replacement of data 
shall be witnessed by a National Board 
Commissioned Inspector and shall be iden- 
tical to the original stamping. 

b) The Re-stamping or replacement of a code 
symbol stamp shall be performed only as 
permitted by the governing code of con- 
struction. 



5.2.1 



AUTHORIZATION 



b) 



When the stamping on a pressure-retaining 
item becomes indistinct or the nameplate is 
lost, illegible, or detached, but traceability 
to the original pressure-retaining item is 
still possible, the Inspector shall instruct 
the owner or user to have the stamped data 
replaced. All re-stamping shall be done 
in accordance with the original code of 
construction, except as modified herein. 
Requests for permission to re-stamp or 
replace nameplates shall be made to the 
Jurisdiction in which the pressure-retain- 
ing item is installed. Application must be 
made on the Replacement of Stamped 
Data Form, NB-136 (See 5.3.2). Proof of 
the original stamping and other such data, 
as is available, shall be furnished with 
the request. Permission from the Jurisdic- 
tion is not required for the reattachment 
of nameplates that are partially attached. 
When traceability cannot be established, 
the Jurisdiction shall be contacted. 

When there is no Jurisdiction, the replace- 
ment of stamped data shall be authorized 
and witnessed by a National Board Com- 
missioned Inspector and the completed 
Form NB-1 36 (See 5.3.2) shall be submitted 
to the National Board. 



c) Replacement nameplates shall be clearly 
marked "replacement." 



5.2.3 



REPORTING 



Form NB-136 shall be filed with the Jurisdic- 
tion (if required) or the National Board by the 
owner or user together with a facsimile of the 
stamping or nameplate, as applied, and shall 
also bear the signature of the National Board 
Commissioned Inspector who witnessed the 
replacement. 



5.3 



5.3.1 



NATIONAL BOARD 
INSPECTION FORMS 



SCOPE 



The following forms may be used for document- 
ing specific requirements as indicated on the 
top of each form. 

Note: Jurisdictions may have adopted other 
forms for the same purpose and may not accept 
these forms. 



88 



NATIONAL BOARD INSPECTION CODE • PART 2 — INSPECTION 



5.3.2 REPLACEMENT OF STAMPED DATA FORM (NB-1 36) 

REPLACEMENT OF STAMPED DATA FORM 
in accordance with provisions of the National Board Inspection Code 



Submitted to 



Submitted by 



(name of jurisdiction) 



(address) 



(name of owner,} 



(address) 



(telephone no.) 

1 . Manufactured by _ 

2. Manufactured for . 



(name and address) 



(name and address) 

3. Location of installation _ 



(address) 



4. Date installed . 



(telephone no.) 



5. Previously installed at 

6. Manufacturer's Data Report attached QNo DYes 

7. Item registered with National Board □ No D Yes, NB Number 

8. Item identification Year built 

Type Dimensions . 



Mfg. serial no. - 
MAWP 



Jurisdiction no. 



. psi Safety relief valve set at . 



psi 

9. Complete the reverse side of this report with a true facsimile of the legible portion 
of the nameplate. 

10. If nameplate is lost or illegible, documentation shall be attached identifying the object to the 
Manufacturer's Data Report referenced on this form. 



11. I request authorization to replace the stamped data and/or nameplate on the above described 
pressure-retaining item in accordance with the rules of the National Board Inspection Code (NBIC). 

Owner or User's name 

Signature 

Title 



. Date . 



12. Authorization is granted to replace the stamped data or to replace the nameplate of the above 
described pressure-retaining item. 



Signature . 



Date . 



(chief inspector or authorized representative) 



Jurisdiction . 



This form may be obtained from The National Board of Boiler and Pressure Vessel Inspectors, 1 055 Crupper Ave., Columbus, OH 43229 



NB-136Rev.6 



89 



NATIONAL BOARD INSPECTION CODE • PART Z — INSPECTION 

The following is a true facsimile of the legible portion of the item's nameplate. Please print. Where 
possible, also attach a rubbing of the nameplate. 



I certify that to the best of my knowledge and belief, the statements in this report are correct, and 
that the replacement information, data, and identification numbers are correct and in accordance 
with provisions of the National Board Inspection Code. Attached is a facsimile or rubbing of the 
stamping or nameplate. 



Name of Owner or User . 



Signature Date 

(authorized representative) 

Witnessed by Employer 

(name of inspector) r J 

Signature Date NB Commission 

(inspector) 



9D 



NATIONAL BOARD INSPECTION CODE • PART 2 — INSPECTION 



5.3.3 



NEW BUSINESS OR DISCONTINUANCE OF BUSINESS FORM (NB-4) 



FORM NB-4 

NEW BUSINESS OR DISCONTINUANCE 

USED BY AUTHORIZED INSPECTION AGENCIES 



To:. 



JURISDICTION 



1. DATE OF SERVICE 



D New insurance business 
2. Notice of: D Discontinuance or cancellation 

D Refusal to insure 



3. Effectve date _ 



4. Type of object: 



D High pressure boiler 
D Low pressure boiler 
D Pressure vessel 



5. OBJECT 



6. OWNER'S NO. 



7. JURISDICTION NO. 



8. NATIONAL BOARD NO, 



9. NAME OF MANUFACTURER 



10. NAME OF OWNER 



1 1 . NAME OF OWNER INCLUDING COUNTY 



12. LOCATION OF OBJECT INCLUDING COUNTY 



1 3. USER OF OBJECT (IF SAME AS OWNER SHOW "SAME") 



14. DATE OF LAST CERTIFICATE INSPECT, IF ANY 



15. CERTIFICATE ISSUED 
□ Yes DNo 



16. REASON FOR DISCONTINUANCE OR CANCELLATION 

□ Phys. condition D Out of use □ Other 



17. REMARKS (USE REVERSE SIDE) 



18. By:. 



CHIEF INSPECTOR 
This form may be obtained from The National Board of Boiler and Pressure Vessel Inspectors, 1 055 Crupper Ave. , Columbus, OH 43229 



BRANCH OFFICE 
NB-4 Rev. 2 



91 



NATIONAL BOARD INSPECTION CODE • PART 2 



INSPECTION 



92 



NATIONAL BOARD INSPECTION CODE • PART 2 INSPECTION 



5.3.4 BOILER OR PRESSURE VESSEL DATA REPORT FORM (NB-5) 

FORM NB-5 BOILER OR PRESSURE VESSEL DATA REPORT 

FIRST INTERNAL INSPECTION 
Standard Form for Jurisdictions Operating Under the ASME Code 



DATE INSPECTED 
MO I DAY I YEAR 



CERT EXP DATE 

MO I YEAR 



CERTIFICATE POSTED 
□ Yes DNo 



OWNER NO. 



JURISDICTION NUMBER 



NATL BD NO. □ OTHER NO.n 



OWNER 



NATURE OF BUSINESS 



KIND OF INSPECTION 



Pint 



□ Ext 



CERTIFICATE 
INSPECTION 
Q&S DNO 



OWNER'S STREET ADDRESS 
NUMBER 



OWNER'S CITY 



STATE 



ZIP 



USER'S NAME - OBJECT LOCATION 



SPECIFIC LOCATION IN PLANT 



OBJECT LOCATION - COUNTY 



USER'S STREET ADDRESS 
NUMBER 



TYPE □ft Owt Dei Dairtank Qwatertank 



Other 



MANUFACTURER 



□ New 

□ Second Hand 



USE □ Power □ Process □ Steam Htg DHWH 

□ Storage □ Heal Exchange n Other 



□ hws 



FUEL (BOILER) 



METHOD OF FIRING (BOILER) 



PRESSURE GAGE TESTED 

Hiss CLNq 



PRESSURE 
This Inspection . 



Prey. Inspection 



SAFETY-RELIEF VALVES 
Set at 



EXPLAIN IF PRESSURE CHANGED 



IS CONDITION OF OBJECT SUCH THAT A CERTIFICATE MAY BE ISSUED? 

- — Q^ s - —J JJ M lJ& ji ^laMll^^ - li s ting c e de Yial s JianL. 



HYDRO TEST 



-BSI— — LB6. 



MUsl. 



SHELL 



DIAMETER □ ID 
i n. POD 



OVERALL LENGTH 

it in_ 



THICKNESS 



TOTAL HTG SURFACE (BOILER) 



Sr| Ft 



MATERIAL 

ASMF Spec Nos 



ALLOWABLE STRESS 



BUTT STRAP 
ILAs 



□ Single 
Jn □ Double 



HEADERS -WT BOILERS 
Thickness 



-Qfiffll f~l Sinuous nwtrWall □ Ot he r - 



TYPE LONGITUDINAL SEAM 
rLLap LlBlI tt n Welded 



n Rra/ed l~l Riveted 



RIVITED 
Die Hole 



PITCH 



in.X 



in.X 



HEAD THICKNESS 



HEAD TYPE □ Fixed 

□ F l U S n Minns l~lFlat 



□ Movable 

□ Quick Opening 



BOLTING 
M. 



Dia. 



in. Material - 



TUBE SHEET THICKNESS 
in 



TUBES 
J* 



Dia. 



length 



PITCH (WT BLRS) 

ira 



LIGAMENT EFF 



FIRETUBE DISTANCE UPPER TUBES TO SHELL 
BOILERS I Front in, Rear 



STAYED AREA 

JnJ FR ON T HFA D 



r Above Tubes _ 

I Relnw Tnhes 



{Above Tubes _ 
Below Tu b e s - 



13 



STAYS ABOVE TUBES 
Front No 



Rear No 



TYPE 

l~l Head to Head 



□ Diagonal 



□ We l de d nweldless 



AREA OF STAYS 
Front 



STAYS BELOW TUBES 

Front No. Rear No. 



TYPE 

n Head tn Head 



□ D i ag onal QfflelrJerJ nweldless 



AREA OF STAYS 

Front 



Roar 



FURNACE -TYPE 
Adamsnn (Nn Sort 



□ Corrugated n Plain 



n Other 



THICKNESS 



TOTAL LENGTH 
It 



TYPE LONG. SEAM 
HWEldEfJ QBiffltfid □ Seamless 



STAYBOLTS-TYPE 
JtllEaSiS f) _ __Wf JjJSSL 



PnlW(Si«Hoif„ 



.£Uk 



SAFETY-RELIEF VALVES 

±La . Size 



TOTAL CAPACITY 



- Lh/Hr 



. Clm 
, Btu/Hr 



OUTLETS 



Si/a 



PROPERLY DRAINED 
Hiss Q 



No III no. explain on hack nl form) 



STOP 
VALVES 



ON STEAM LINE 

□Ye s nNn 



ON RETURN LINES 
Hiss DNO 



OTHER CONNECTIONS 
□ Ye s QNfl 



STEAM LINES PROPERLY DRAINED 

riYes n No (If no explain on hack of 



fonn'i 



FEEDPIPE 



FEED APPLIANCES 
No. 



TYPE DRIVE 
l~l Steam 



l~l Motor 



CHECK 
VALVES 



FEED LINE 
HlSS 



□ No 



RETURN LINE 
Hiss DNO 



WATER GAGE GLASS 

Jo. 



TRY COCKS 
No 



BLOWOFFPIPE 
-Size in. Location 



INSPECTION OPENINGS COMPLY WTH CODE 

□ Yes riNn»fnn explain on hack of farm) 



CAST-IRON BOILERS 

I enclh 



_UL Width _ 



Jo Height 



SECTIONS 

iJa 



DOES WELDING ON STEAM. FEED BLOWOFF AND OTHER PIPING COMPLY WITH CODE 
HiSS □ No j H nn. explain on hack nl form) 



SHOW ALL CODE STAMPING ON BACK OF FORM. Give details (use sketch) for 
special objects NOT covered above -such a s Double wall vessels etc. 



DOES ALL MATERIAL OTHER THAN AS INDICATED ABOVE COMPLY WITH CODE 
Hiss Otto W no. explain on hack ol form) 



NAME AND TITLE OF PERSON TO WHOM REQUIREMENTS WERE EXPLAINED: 



I HEREBY CERTIFY THIS IS A TRUE REPORT OF MY INSPECTION 

Signature 

of Inspector 



IDENT NO. 



EMPLOYED BY 



This form may be obtained from The National Board of Boiler and Pressure Vessel Inspectors, 1055 Crupper Ave., Columbus, OH 43229 



NB-5 Rev. 



93 



NATIONAL BOARD INSPECTION CODE " PART Z — INSPECTION 



OTHER CONDITIONS AND REQUIREMENTS 



CODE STAMPING 



(BACK) 



94 



NATIONAL BOARD INSPECTION CODE • PART 2 — INSPECTION 



5.3.5 BOILER-FIRED PRESSURE VESSELS REPORT OF INSPECTION FORM (NB-6) 

FORM NB-6 BOILER-FIRED PRESSURE VESSEL 

REPORT OF INSPECTION 

Standard Form for Jurisdictions Operating Under the ASME Code 



DATE INSPECTED 
MO I DAY I YEAR 



CERT EXP DATE 
MO I YEAR 



CERTIFICATE POSTED 
□ Yes DNo 



OWNER NO. 



OWNER 



OWNER'S STREET ADDRESS 
NUMBER 



USER'S NAME - OBJECT LOCATION 



USER'S STREET ADDRESS 
NUMBER 



TYPE 

□ FT □ WT □ CI □ Other _ 



YEAR BUILT 



USE 



□ Power □ Process □ Steam Htg DHWH DHWS □Other. 



JURISDICTION NUMBER 



NAT'LBDNO.a OTHER NO. □ 



NATURE OF BUSINESS 



KIND OF INSPECTION 
□ Int □ Ext 



CERTIFICATE INSPECTION 

□ Yes □ No 



OWNER'S CITY 



SPECIFIC LOCATION IN PLANT 



OWNER'S CITY 



STATE 



ZIP 



OBJECT LOCATION - COUNTY 



STATE 



ZIP 



MANUFACTURER 



FUEL 



METHOD OF FIRING 



PRESSURE ALLOWED MAWP 

This Inspection Prev. Inspection _ 



SAFETY-RELIEF VALVES 

Set at Total Capacity _ 



PRESSURE GAGE TESTED 
□ Yes □ No 



HEATING SURFACE OR BTU (Input/Output) 



IS CONDITION OF OBJECT SUCH THAT A CERTIFICATE MAY BE ISSUED? 
□ Yes □ No (II no, explain fully under conditions) 



HYDRO TEST 
□ Yes 



_ psi Date . 



□ No 



CONDITIONS: With respect to the internal surface, describe and state location of any scale, oil or other deposits. Give location and extent of any corrosion and state whether active or 
inactive. State location and extent of any erosion, grooving, bulging, warping, cracking or similar condition. Report on any defective rivits, bowed, loose or broken stays. State condition of all 
tubes, tube ends, coils, nipples, etc. Describe any adverse conditions with respect to pressure gage, water column, gage glass, gage cocks, safety valves, etc. Report condition of setting, 
linings, baffles, supports, etc. Describe any major changes or repairs made since last inspection. 



10 



REQUIREMENTS: (List Code Violations) 



NAME AND TITLE OF PERSON TO WHOM REQUIREMENTS WERE EXPLAINED: 



I HEREBY CERTIFY THIS IS A TRUE REPORT OF MY INSPECTION 



SIGNATURE OF INSPECTOR 



IDENT NO. 



EMPLOYED BY 



IDENT NO. 



This form may be obtained from The National Board of Boiler and Pressure Vessel Inspectors, 1 055 Crupper Ave., Columbus, OH 43229 



NB-6 Rev. 4 



95 



NATIONAL BOARD INSPECTION CODE • PART 2 



INSPECTION 



96 



NATIONAL BOARD INSPECTION CODE • PART 2 — INSPECTION 



5.3.6 PRESSURE VESSELS REPORT OF INSPECTION FORM (NB-7) 

FORM NB-7 PRESSURE VESSELS 
REPORT OF INSPECTION 

Standard Form for Jurisdictions Operating Under the ASME Code 



DATE INSPECTED 
MO I DAY I YEAR 



CERT EXP DATE 
MO I YEAR 



CERTIFICATE POSTED 
DYes DNo 



OWNER NO 



JURISDICTION NUMBER 



NATL BD NOD OTHER NO. □ 



NATURE OF BUSINESS 



KIND OF 
INSPECTION 
D Int □ Ext 



CERTIFICATE 
INSPECTION 
DYes DNo 



OWNER'S STREET ADDRESS 



OWNER'S CITY 



STATE 



ZIP 



USER'S NAME ■ OBJECT LOCATION 



SPECIFIC LOCATION IN PLANT 



OBJECT LOCATION -COUNTY 



USER'S STREET ADDRESS 



STATE 



TYPE 

D AIR TANK 



D WATER TANK □ OTHER 



YEAR 
BUILT 



MANUFACTURER 



USE 

□ STORAGE 



SIZE 



□ PROCESS 



□ HEAT EXCHANGE D OTHER 



PRESSURE GAGE TESTED 
DYes DNo 



PRESSURE ALLOWED 
THIS INSPECTION 



PREVIOUS INSPECTION 



SAFETY RELIEF VALVES 

SET AT TOTAL CAPACITY 



EXPLAIN IF PRESSURE CHANGED 



IS CONDITION OF OBJECT SUCH THAT A CERTIFICATE MAY BE ISSUED? 
□ YES D NO (IF NO, EXPLAIN FULLY UNDER CONDITIONS) 



HYDRO TEST 
DYES 



_ PSI DATE_ 



.□NO 



CONDITIONS; 

With respect to the internal surface, describe and state location of any scale, oil or other deposits. Give location and extent of any corrosion and state whether active or inactive. Slate location and extent of any 
erosion, grooving, bulging, warping, cracking or similar condition. Report on any defective rivits, bowed, loose or broken stays. State condition of all tubes, tube ends, coils, nipples, etc. Describe any adverse 
conditions with respect to pressure gage, water column, gage glass, gage cocks, safety valves, etc. Report condition of setting, linings, baffles, supports, etc. Describe any major changes or repairs made since 
last inspection. 



REQUIREMENTS: (LIST CODE VIOLATIONS) 



10 



NAME AND TITLE OF PERSON TO WHOM REQUIREMENTS WERE EXPLAINED: 



HEREBY CERTIFY THIS IS A TRUE REPORT OF MY INSPECTION 



SIGNATURE OF INSPECTOR 



EMPLOYED BY 



This form may be obtained from The National Board of Boiler and Pressure Vessel Inspectors, 1055 Crupper Ave., Columbus, OH 43229 

97 



NB-7 Rev. 2 



NATIONAL BOARD INSPECTION CODE • PART 2 — INSPECTION 



5.3.6-a 



PRESSURE VESSEL 




REPORT OF INSPECTION — (EXTENSION SHEET) 




DATE INSPECTED 


OWNER-USER 


LOCATION 


OWNER'S 
NO. 


JURISDICTION 
NO. 


NB 
ASM E OR 
STD. NO. 


INT 


EXT 


*CERT- 
NO.OF 
YEARS 


TYPE OF OBJECT 


YEAR 
BUILT 


MADE BY 


ALLOW. 
PRESS. 


TEMP. 
OF 


R.V.S.V. 

SETTING 










































































































































































































































































































































































































































































































































































































































































































































































* In this colum 


n show the m 


mberofyea 


rstor 


whic 


i the inspe 


ctor authorizes the issuance 


ot the certi 


icate. 









98 



NATIONAL BOARD INSPECTION CODE • PART 2 INSPECTION 



5.3.7 REPORT OF FITNESS FOR SERVICE ASSESSMENT FORM (NB-403) 



The National Board of Boiler and Pressure Vessel Inspectors 

REPORT OF FITNESS FOR SERVICE ASSESSMENT 



1 . Equipment Owner Information: 



F.F.S. Assessment No. 

& 

(Name) 



HI 



2. FFS Assessment Performed By: 



(Address) 

© 



(Name of Organization or Individual) 



3. Location of Equipment Installation: . 



(Address) 



(Name of Company) 



© 



4. Equipment or Component Information 



(Address) (Jurisdiction) 

© 



(MFG SR#, NB#, Jurisdiction# , Year Built, Other) 



(Equipment Material Specification, Grade) 



5. Original Code of Construction 



(Design & Operating Pressures, Design & Operating Temperatures) 

© 



(Name) (Section) (Division) (Edition) (Addendum) 



FITNESS FOR SERVICE STANDARD USED FOR ASSESSMENT 



©. 



6. Flaw Type(s) and/or Damage Mechanisms considered in FFS Assessment: 



©_ 



7. FFS Assessment Procedures (attach FFS Assessment reference documents with details if applicable): 



®_ 



Inspection Results 



A©. 



(Type of NDE Performed, Pressure Tests, Thickness Measurements, etc.) 



Failure Modes Identified 



:@L 



(Crack-Like Flaws. Pitting. Bulges/Blisters, General or Localized Corrosion, etc.) 



99 



NATIONAL BOARD INSPECTION CODE • PART 2 — INSPECTION 



8. FFS Assessments Results / Recommendations (Check boxes that apply and provide details): (13) ^. 
□ Continued Operation J^ Repair J^Replace ^Continue Operation Until: S^J- 



Details (if applicable) . 



9. Owners Inspection Intervals (Based on Assessment): 

® 



® 



(Months/Years) 



10. Inservice Monitoring Methods and Intervals: 



11. Operating Limitations (if applicable): 



(Methods, Months/Years) 



I,. 



. certify that to the best of my knowledge and belief 



the statements in this report are correct and that the information, data, and identification numbers are 
correct and in accordance with provisions of the National Board Inspection Code, Part 2, 4.4. Applicable 
documentation is attached to support this assessment. 



Owner Name. 



& 



(Printed) 



Signature . 



Sl 



Date. 



Organization Performing Assessment 
Signature \^s 



(Owner) 



(Name) 



Date . 



(Responsible Engineer) 



Verified By . 



. Employer 



& 



(Inspector, Printed) 



Signature . 



(Accredited Inspection Agency) 

® 



Date. 



(Inspector) 



NB Commission # 



® 



(National Board & 
Jurisdiction Number) 



This form may be obtained from The National Board of Boiler and Pressure Vessel Inspectors, 1055 Crupper Ave., Columbus, OH 43229 



1 DO 



NATIONAL BOARD INSPECTION CODE « PART 2 



INSPECTION 



5.3.7.1 GUIDE FOR COMPLETING 
FSTNESS FOR SERVICE 
ASSESSMENT REPORTS 

1. For tracking and reference purposes indi- 
cate the sequential Fitness for Service 
Assessment number. 



1 1 . Description of the Inspection and NDE re- 
sults as prescribed in the Fitness for Service 
Assessment analysis. 

12. Description of the Failure, Damage and/or 
Deterioration modes identified in the Fit- 
ness for Service Assessment. 



2. Name and address of the owner of the 
equipment that is being assessed for Fitness 
for Service. 



13. Indicate the results of the Fitness for Service 
Assessment, including remediation recom- 
mendations. 



3. Name and address of the organization or 
individual performing the Fitness for Ser- 
vice Assessment. 

4. Name and address of the facility where the 
equipment being assessed for Fitness for 
Service is located. 

5. Name of the Jurisdiction where the assessed 
equipment is located. 

6. Identification of Equipment including 
Manufacturer, Manufacturer's serial num- 
ber, National Board Number, Jurisdiction 
assigned registration number, and Year 
built. Also include Equipment/Component 
Material Specification/Grade, Design and 
Operating Pressures, Design and Operating 
Temperatures, if applicable. 

7. Indicate the name, section, division, edi- 
tion, and addenda of the original Code of 
Construction. 

8. Name of the Standard used to perform the 
Fitness for Service Assessment. 

9. Description of the Equipment/ Component 
damage mechanism or flaw types consid- 
ered in the Fitness for Service Assessment. 

10. Description of the Fitness for Service As- 
sessment level and technique. Attach all 
relevant Fitness for Service Assessment 
procedures and detailed documentation. 



14. Indicate if the equipment can continue 
current operation. 

1 5. Indicate if repairs are required. 

16. Indicate if equipment replacement is re- 
quired. 

1 7. Indicate if continued operation has a finite 
date. 

1 8. Indicate finite date of continued operation 
(if applicable). 

19. Indicate the required Inspection intervals 
as determined by the Fitness for Service 
Assessment. 

20. Indicate the required inservice monitoring 
methods and intervals for the equipment as 
defined by the Fitness for Service Assess- 
ment. 

21 . Describe any operating or inservice limita- 
tions for the equipment. This would include 
any reductions / changes in operating pres- 
sures or temperatures. 

22. Type or print the name of the representative 
of the Organization or individual perform- 
ing the Fitness for Service Assessment. 

23. Name of the Owner of the equipment. 

24. Signature of Owner. 



i a i 



NATIONAL BOARD INSPECTION CODE • PART Z — INSPECTION 



25. Indicate the month, day, and year of the 
Owner review and acceptance of Fitness 
for Service Assessment. 

26. Indicate the name of the organization per- 
forming the Fitness for Service Assessment 
(this may be the same name as in line 22) 

27. Signature of the responsible engineer 
performing the Fitness for Service Assess- 
ment. 

28. Indicate the month, day, and year of the 
completion of the Fitness for Service Assess- 
ment by the Organization responsible. 

29. Type or print the name of the Inspector. 

30. Name of the Accredited Inspection Agency 
employing the Inspector. 

31 . Signature of the Inspector. 

32. Indicate the month, day, and year of the 
review and acceptance by the Inspector of 
the Fitness for Service Assessment. 

33. National Board commission number of 
Inspector, Jurisdiction, and Certificate of 
Competency Numbers. 



1 D2 



Insert 

Section 6 
Tab 

Here 




Part 2, Section G 
Inspection — Supplements 



1 D3 



NATIONAL BOARD INSPECTION CODE • PART 2 — INSPECTION 

PART 2, SECTION 6 

INSPECTION — SUPPLEMENTS 



6.1 



SCOPE 



a) This section contains detailed inspection 
requirements for specific pressure-retaining 
items identified as Supplements. 

b) Inspection of items described in these 
Supplements may include application of 
additional inspection requirements con- 
tained in other sections of Part 2. 

c) Each Supplement is numbered in sequential 
order and follow the same numbering sys- 
tem used for the main text only preceded 
by the letter "S." Each page of the Supple- 
ment will identify the supplement name 
and number in the top heading. 



SUPPLEMENT 1 

STEAM LOCOMOTIVE 
FIRETUBE BOILER INSPECTION 
AND STORAGE 



S1.1 



SCOPE 



This supplement is provided as a guide for 
inspection and storage of steam locomotive 
firetube boilers. These rules shall be used in 
conjunction with the applicable rules of the 
NBIC. See Figures S1 .1 -a and S1 .1 -b. 



S1.2 SPECIAL JURISDICTIONAL 

REQUIREMENTS 

Many Jurisdictions have special requirements 
for locomotive boilers. Such requirements 
shall be considered in addition to those in this 
supplement. 



FIGURE S1.1-a 

Locomotive Boiier General Arrangement 



Smokebox and Shell Ring 



Smokebox 




Back Tubesheet 



Front Tubesheet 



1 D4 



NATIONAL BOARD INSPECTION CODE * PART Z 



INSPECTION 



FIGURE Sl.l-b 

Arrangement of Firebox Sheets (Staybolts Deleted for Clarity) 



Dome Course 




Crown Sheet 



Throat Sheet 



Inside Throat Sheet 








S1.3 FEDERAL RAILROAD 

ADMINISTRATION (FRA) 



S1.4 LOCOMOTIVE FIRETUBE 

BOILER INSPECTION 



The FRA rules for steam locomotive boilers 
are published in the Code of Federal Regula- S1 
tions (CFR) 49CFR Part 230, dated November 
1 7,1 999.1 - 1 All locomotives under FRA Juris- a) 
diction are documented on FRA Form 4 as 
defined in 49CFR Part 230. This document is 
the formal documentation of the steam loco- 
motive boiler and is required to be completed b) 
prior to the boiler being placed in service. This 
document shall be used as the data report for 
the boiler, applicable to all repairs and altera- 
tions performed. National Board "R" Certificate c) 
Holders shall document their repairs and/or 
alterations on National Board Forms R-1 or 
R-2. These reports shall be distributed to the 
owner-user of the boiler, who is required to 
incorporate them into the FRA Form 1 9, which 
becomes an attachment to the FRA Form 4. The 
design margin for all such repairs or alterations 
shall not be less than four based on ultimate 
tensile strength of the material. 

d) 



4.1 



INSPECTION METHODS 



1 Steam locomotive inspection and maintenance standards, 
which is now codified at 49CFR Part 230, may be obtained at 
the FRA Web site. The final rule at www.fra.dot.gov/downIoads/ 
counsel/fr/slfr.pdf 



Plate thickness and depth of corrosion may 
be determined by use of the ultrasonic 
thickness testing process. 

Where access is possible, the depth of pit- 
ting may be determined by use of a depth 
micrometer or a pit gage. 

On stayed sections, the plate thickness 
readings should be taken on a grid not 
exceeding the maximum staybolt pitch at 
the center of each section of four staybolts. 
Additional readings may be taken close 
to each staybolt to determine if localized 
thinning has occurred. Particular attention 
should be given to the joint between the 
staybolt and the plate. 

On unstayed sections, the plate thickness 
readings should be taken on a grid not 
exceeding 12 inch (305 mm) centers. Ad- 
ditional readings should be taken if condi- 
tions warrant. 



1 05 



NATIONAL BOARD INSPECTION CODE • PART 2 



INSPECTION 



e) Cracks in plates may be located by the use 
of appropriate Nondestructive Examination 
(NDE) methods. 

f) Separation of plates at riveted seams may be 
detected by use of a feeler gage and mag- 
nifying glass or other applicable method. 

g) Varying the intensity of inspection lights 
may facilitate discovery of defects. Place- 
ment of the light to shine parallel to the 
surface is one method of detecting pits and 
surface irregularities. 

h) When inspecting internal stayed surfaces, 
placement of a light source within the 
stayed zone will aid the inspection. 

i) Broken staybolts may be detected by leak- 
age through telltale holes and by hammer 
testing. Both methods are most effective 
when the boiler is under hydrostatic pres- 
sure of at least 95% MAWP. If a hydrostatic 
test cannot be applied, the hammer test 
may be performed alone with the boiler 
drained. 

j) Visual inspection shall be performed as a 
supplement to all of the above. 



S1.4.2 



INSPECTION ZONES 



S1 .4.2.1 RIVETED SEAMS AND RIVET 
HEADS 

Riveted seams and rivet heads shall be in- 
spected for: 

a) Grooving 

b) Corrosion 

c) Cracks 

d) Pitting 

e) Leakage 



f) Separation of the plates 

g) Excessive or deep caulking of the plate 
edges and rivet head 

h) Seal welding of the plate edges and rivet 
heads 

i) Rivet heads that have been built up by or 
covered over completely by welding 

j) Rivets replaced by patch bolts 

k) Defective components of the seam 

Notes: Broken rivet heads or cracked plates 
may result from sodium hydroxide cracking 
(caustic embitterment). 

Riveted longitudinal lap seams should be 
given careful examination, using NDE if 
necessary, because this type of construction 
is prone to cracking. 

When determining the extent of corrosion 
to rivet heads, it is important to know the 
rivet size and the type of rivet head used 
for the original construction. Corrosion can 
alter the appearance of these items and 
disguise the full extent of the damage. 

Fire cracks extending to the rivet holes in 
riveted lap seams of firebox sheets may be 
acceptable under 3.4.9. 



S1 .4.2.2 WELDED AND RIVETED REPAIRS 

Welded and riveted repairs shall be inspected 
for: 

a) Correct application of welded patches or 
weld application 

b) Correct application of riveting 

c) Cracks 

d) Separation of the plates 



l ne 



NATIONAL BOARD INSPECTION CODE • PART Z — INSPECTION 



e) Dents or other mechanical damage 

f) Leakage 

51 .4.2.3 BOILER SHELL COURSE 

The boiler shell course shall be inspected for: 

a) Grooving or cuts 

b) Corrosion 

c) Cracks 

d) Pitting 

e) Separation of the plates 

f) Dents or other mechanical damage 

g) Leakage 

Note: An accurate inspection often cannot 
be performed until the interior has been 
cleaned since mud and scale make it dif- 
ficult to detect defects. 

51 .4.2.4 DOME AND DOME LID 

The dome and dome lid shall be inspected 
for: 

a) Grooving 

b) Corrosion, especially at the interior section 
attached to the boiler course 

c) Cracks 

d) Pitting 

e) Separation of plates 

f) Dents or other mechanical damage 

g) Leakage 



h) Stretched, bent, or corroded dome studs 

i) Damage to the steam dome cover sealing 
surfaces 

Notes: Close inspection should be made to 
the interior section at the joint attached to 
the boiler course. 

If the dome studs are bent, a careful evalu- 
ation should be made of the lid for leakage 
and mechanical damage. 



51.4.2.5 MUDRING 

The mudring and mudring rivets shall be in- 
spected for: 

a) Mud and scale on the waterside 

b) Debris on the waterside 

c) Corrosion 

d) Grooving 

e) Cracks 

f) Separation of the firebox plates from the 
mudring 

g) Dents or other mechanical damage 
h) Leakage 

51 .4.2.6 FLUE SHEETS 

Flue sheets shall be inspected for: 

a) Grooving around flue holes, rivet seams 
and braces 

b) Pitting 

c) Fireside and waterside corrosion 

d) Fire cracks at riveted lap seams 



1 D7 



NATIONAL BDARD INSPECTION CODE • PART Z — INSPECTION 



e) Cracks 

t) Bulges 

g) Leakage 

h) Excessive or deep caulking of the plate 
edges 

Note: Corrosion is common at the bottom 
section of the front flue sheet. Close inspec- 
tion of the joint between the front flue sheet 
and shell shall be made. 

51 .4.2.7 FLANGED SHEETS 

The flanged section of all flanged sheets shall 
be inspected for: 

a) Pitting 

b) Corrosion 

c) Cracks 

d) Grooving 

e) Scale and mud deposits 

f) Correct fit up and alignment of the flanged 
sheet to the adjacent sheets 

Notes: Corrosion is common at the bottom 
section of the front flue sheet. 

The flanges should have a smooth uniform 
curvature and should make a smooth transi- 
tion to the flat sheets. 

51 .4.2.8 STAYED SHEETS 

Stayed sheet shall be examined for: 

a) Scale and mud deposits 

b) Grooving around staybolt holes 



c) Deterioration of the joint between the stay- 
bolt and the sheet 

d) Grooving on the waterside section 

e) Pitting 

f) Fireside and waterside corrosion 

g) Overheating 

h) Fire cracks at riveted lap seams 

i) Cracks 

j) Bulges 

Notes: Close inspection for fireside corro- 
sion should be given to sections located 
behind refractory or grate bars. 

Close inspection should be made for groov- 
ing on waterside surfaces of the stayed 
sheets just above the mudring. 

Fire cracks extending to the rivet holes in 
riveted lap seam firebox sheets may be ac- 
ceptable under 3.4.9. 

S1 .4.2.9 STAYBOLTS 
Staybolts shall be inspected for: 

a) Cracks in or breakage of the body 

b) Erosion of the driven head from corrosion 
or combustion gases 

c) Staybolt head flush with or below the sur- 
face of the sheet 

d) Plugging of telltale holes except as permit- 
ted by 49 CFR Part 230.41 

e) Waterside corrosion 

f) Staybolt heads that have been covered over 
by welding 



i as 



NATIONAL BOARD INSPECTION CODE • PART 2 



INSPECTION 



Correct application of seal welding to stay- 
bolt heads 

Notes: An indicator of waterside corrosion 
on threaded staybolts is the lack of threads 
on the section of the staybolt body just 
above the sheet. 

Broken staybolts may be detected by leak- 
age through telltale holes and by hammer 
testing. Both methods are most effective 
when the boiler is under hydrostatic pres- 
sure of at least 95% MAVVP. If a hydrostatic 
test cannot be applied, the hammer test 
may be performed alone with the boiler 
drained. 

When a broken stay is found, the stays 
adjacent to it should be examined closely 
because these may have become over- 
stressed by addition of the load from the 
broken stay. 

A telltale hole plugged by installation of 
a nail or pin may indicate the staybolt is 
broken and requires replacement. 

The plugging of telltale holes by refractory 
to prevent build up of foreign matter in the 
telltale hole is permitted for locomotives 
operating under FRA Jurisdiction per 49 
CFR Section 230.41. 

One indication that a threaded staybolt 
leaks during service is when the head of it is 
found to have been re-driven repeatedly. 



S1.4.2.10 FLEXIBLE STAYBOLTS AND 

SLEEVES 

Flexible staybolt sleeves and caps shall be 
inspected for: 

a) Corrosion 

b) Cracks 

c) Dents or other mechanical damage 



d) Leakage 

e) Damaged threads or welds 

f) Scale and mud accumulations inside the 
sleeve that could restrict bolt movement 

g) Correct application of welding to welded 
sleeves and welded caps 

h) Seal welding of threaded sleeves or thread- 
ed caps 

Notes: An indicator of waterside corrosion 
on threaded staybolts is the lack of threads 
on the section of the staybolt body just 
above the sheet. 

Broken staybolts may be detected by leak- 
age through telltale holes and by hammer 
testing. Both methods are most effective 
when the boiler is under hydrostatic pres- 
sure of at least 95% MAVVP. If a hydrostatic 
test can not be applied, the hammer test 
may be performed alone with the boiler 
drained. 

On ball head flexible staybolts, one method 
of testing the stay for cracks or breakage is 
to strike the ball head using a pneumatic 
hammer or hand hammer. Another method 
is to twist the ball head using a long handle 
wrench. Access to the ball head is gained 
by removing the cap from the sleeve. 

When a broken stay is found, the stays 
adjacent to it should be examined closely 
because these may have become over- 
stressed by addition of the load from the 
broken stay. 

A telltale hole plugged by installation of 
a nail or pin may indicate the staybolt is 
broken and requires replacement. 

The plugging of telltale holes by refractory 
to prevent build up of foreign matter in the 
telltale hole is permitted for locomotives 
operating under FRA Jurisdiction per 49 
CFR Section 230.41. 



1 D9 



NATIONAL BOARD INSPECTION CODE ' PART 2 



INSPECTION 



One indication that a threaded staybolt 
leaks during service is when the head of it is 
found to have been re-driven repeatedly. 



because these may have become over- 
stressed by addition of the load from the 
broken stay. 



S1 .4.2.11 GIRDER STAY AND CROWN 
BARS 

Girder stays, crown bars, and their associated 
fasteners including stays, rivets, pins, washers, 
nuts, thimbles, spacers, and the adjacent sec- 
tions of the firebox plates shall be inspected 

for: 

a) Corrosion 

b) Cracks 

c) Mud and scale 

d) Correct fit and alignment of the girder stay 
or crown bar to the firebox plate surface, 
including flanged sections 

e) Correct fit and alignment of the thimbles, 
spacers, and pins to the girder stay or crown 
bar, and the firebox plates 

f) Dents or other mechanical damage 

g) Stays or rivets built up by or covered over 
completely by welding 

h) Leakage from the stay heads 

i) Seal welding of rivet heads 



Correct application of retainers to all nuts 
and fasteners 



J) 

k) Missing fasteners, nuts or retainers 



Notes: An accurate inspection often cannot 
be performed until the girder stay or crown 
bar has been cleaned since mud and scale 
will make it difficult to detect defects. 

When a broken stay is found, the stays 
adjacent to it should be examined closely 



S1 .4.2.1 2 SLSNG STAYS 

Sling stays and their associated fasteners includ- 
ing the pins, retainers, washers, nuts, and their 
associated attachment at eyes, girder stays, or 
crown stays shall be inspected for: 

a) Corrosion 

b) Cracks 

c) Dents, wear or other mechanical damage 

d) Mud and scale 

e) Wear to the pin hole or expansion slot of 
the sling stay and mating component 

f) Correct application of retainers to the 
pins 

g) Missing fasteners, nuts, or retainers 

h) Any of the above that would restrict move- 
ment of the sling stays 

Notes: An accurate inspection often cannot 
be performed until the sling stay has been 
cleaned since mud and scale will make it 
difficult to detect defects. 

When a broken or loose stay is found, the 
stays adjacent to it should be examined 
closely because these may have become 
overstressed by addition of the load from 
defective stay. 

Special attention should be given to the row 
of sling stays adjacent to the flue sheet to 
ensure that these stays are not loose. 



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NATIONAL BOARD INSPECTION CODE • PART 2 — INSPECTION 



S1 .4.2.1 3 CROWN STAYSAND 
EXPANSION STAYS 

Crown stays and expansion stays shall be in- 
spected for: 

a) Cracks in or breakage of the body 

b) Dents, wear, or other mechanical damage 

c) Erosion of the driven head from corrosion 
or combustion gases 

d) Stay head flush with or below the surface 
of the sheet 

e) Plugging of telltale holes, except as permit- 
ted by 49 CFR Part 230.41 

f) Waterside corrosion 

g) Stay heads that have been covered over by 
welding 

h) Correct application of seal welding to stay 
heads 

i) Correct application of retainers to the 
pins 

j) Missing fasteners, nuts, or retainers 

k) Correct fit and alignment of the stay as- 
sembly 

I) Any of the above that would restrict move- 
ment of the stay 

Notes: An indicator of waterside corrosion 
on threaded stays is the lack of threads on 
the section of the stay body just above the 
sheet. 

Broken stays may be detected by leakage 
through telltale holes and by hammer test- 
ing. Both methods are most effective when 
the boiler is under hydrostatic pressure of at 
least 95% MAVVP. If a hydrostatic test can 



not be applied, the hammer test may be 
performed alone with the boiler drained. 

When a broken stay is found, the stays ad- 
jacent to it should be examined closely be- 
cause these may have become overstressed 
by addition of the load from broken stay. 

A telltale hole plugged by installation of a 
nail or pin may indicate the stay is broken 
and requires replacement. 

The plugging of telltale holes by refractory 
to prevent build up of foreign matter in the 
telltale hole is permitted for locomotives 
operating under FRA Jurisdiction per 49 
CFR Part 230.41. 

One indication that a threaded stay leaks 
during service is when the head of it is 
found to have been re-driven repeatedly. 

Special attention should be given to the row 
of stays adjacent to the flue sheet to ensure 
that these stays are not loose. 



S1.4.2.14 DIAGONAL AND GUSSET 
BRACES 

Diagonal and gusset braces, and their attach- 
ments, shall be inspected for: 

a) Looseness 

b) Corrosion 

c) Cracks 

d) Welded repairs 

e) Missing pins or pin retainers 

f) Defective rivets 

g) Scale and mud deposits 

Notes: Diagonal and gusset braces should 
be under tension. 



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NATIONAL BOARD INSPECTION CODE • PART Z — INSPECTION 



The brace pins should fit the brace clevis 
and eye securely and be retained from 
coming out by some type of fixed or keyed 
retainer. 

Diagonal braces having loop-type ends 
should be given close inspection for cracks 
and corrosion. The loop-type end is formed 
by the brace body being split, looped 
around, and forged to the body. Some ver- 
sions of it have a low margin of material to 
provide the required strength. 



S1 .4.2.1 5 FLUES 

All boiler and super heater flues shall be in- 
spected for: 

a) Fire cracks 

b) Pitting 

c) Corrosion 

d) Erosion 

e) Obstructions in the flue interior 

f) Mud or scale buildup on the waterside 

g) Erosion or cracking of the flue ends, flue 
beads and/or seal welds 

h) Leakage 

i) Number of circumferential welded joints 
on flues repaired by re-ending 

j) Correct application including expanding/ 
rolling and belling, beading, or seal weld- 
ing of the flue end 

Notes: Erosion (cinder cutting) generally 
occurs to the firebox end of the flue. 

Galvanic corrosion of the flue in the flue 
sheet may occur if flues are installed with 
copper ferrules. 



51.4.2.16 SUPERHEATER UNITS AND 
HEADER 

Superheater units and the superheater header 
shall be inspected for: 

a) Pitting 

b) Cracks 

c) Erosion 

d) Corrosion 

e) Bulges 

f) Leakage 

g) Missing shields 

h) Missing or broken bands or supports on the 
superheater units 

i) Missing, damaged, or welded attachment 
bolts, nuts, clamps, studs, and washers 

j) Adequate structural bracing and support of 
the superheater header 

51 .4.2.1 7 ARCH TUBES, WATER BAR 
TUBES AND CIRCULATORS 

Arch tubes, water bar tubes, and circulators 
shall be inspected for: 

a) Erosion 

b) Corrosion 

c) Fire cracks 

d) Pitting 

e) Cracking of tube ends 

t) Overheating and blistering 
g) Bulges 



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NATIONAL BOARD INSPECTION CODE • PART Z — INSPECTION 



h) Mud and scale buildup in the waterside 

i) Welded repairs 

j) Correct application including expanding/ 
rolling and belling, beading, or seal weld- 
ing of the tube end 

Note: Weld buildup or welded patches are 
not permitted on arch tubes and water bar 
tubes of locomotives operating under FRA 
Jurisdiction per 49 CFR Section 230.61 . The 
defective tubes must be replaced. 



51 .4.2.1 8 THERMIC SYPHONS 

Thermic syphons shall be inspected for: 

a) Erosion 

b) Corrosion 

c) Fire cracks 

d) Pitting 

e) Cracking of the syphon neck 

f) Overheating and blistering 

g) Bulges 

h) Mud and scale blockage in the waterside 

i) Broken or damaged staybolts 

Note: Refer to inspection zones — Stay- 
bolts, Stayed Sheets, and Flanged Sheets 
for additional inspection procedures. 

51.4.2.19 FIREBOX REFRACTORY 

Firebox refractory shall be inspected to ensure 
it is properly applied and maintained to prevent 
undesired flame impingement on the firebox 
sheets. 



SI. 4.2.20 DRY PIPE 

The dry pipe of boilers having dome mounted 
(internal) throttle valves shall be inspected 

for: 

a) Erosion 

b) Corrosion 

c) Cracks 

d) Adequate structural bracing, support, and 
attachment to the boiler and dome 

e) Loose, bent or damaged rivets, nuts, bolts, 
and studs 

Note: A steam leak into the dry pipe of a 
dome mounted (internal) throttle valve will 
send an unregulated flow of steam to the 
cylinders. 



S1 .4.2.21 THROTTLE AND THROTTLE 
VALVE 

The throttle handle and its mechanism shall be 
inspected for: 

a) Proper operation 

b) Lost motion or looseness 

c) Adequate structural bracing, support and at- 
tachment to the boiler, dome, and firebox 

d) Loose, bent or damaged nuts, bolts, and 
studs 

Note: The throttle handle shall be equipped 
with some type of locking mechanism to 
prevent the throttle from being opened by 
the steam pressure. 



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NATIONAL BOARD INSPECTION CODE • PART Z — INSPECTION 



S1 .4.2.22 SCREW-TYPE WASHOUT PLUGS, 
HOLES, AND SLEEVES 

Screw-type washout plugs, holes, and sleeves, 
especially those having square or Acme thread, 
shall be inspected for: 

a) Damaged or cracked threads on the plug, 
hole, or sleeve 

b) Corrosion 

c) Cracks 

d) Distortion 

e) Looseness 

f) Leakage 

g) Steam cuts to threads and sealing surfaces 

h) Twisting of the plug head or body 

Note: When washout plugs are threaded 
with USF or NPT thread, the minimum 
number of threads in good condition in 
the threaded hole shall be adequate for the 
service. 



f) Leakage and steam cuts 

g) Damage to the clamp 

h) Damage to the clamp seating surface on 
the sheet 

i) Confirmation that the handhole door makes 
unbroken line contact along the entire cir- 
cumference of the sheet at the opening 

j) Material of the handhole door gaskets 

k) Correct repairs 

Notes: Confirmation that the handhole 
door has unbroken line contact against 
sheet can be determined by performing a 
"blue check." This requires applying a light 
coating of "contact blue" or "Prussian Blue" 
to the handhole door sealing surfaces. The 
door then is held against the sheet and re- 
moved. The transfer of the bluing will show 
the areas that contact the sheet surfaces. 

The material of the handhole door gaskets 
should be reviewed with the operator to 
confirm that it meets the pressure and tem- 
perature requirements of the boiler. 



S1 .4.2.23 HANDHOLE WASHOUT DOORS 

Handhole washout doors and their mating 
surfaces shall be inspected for: 

a) Damaged or cracked threads on the door 
studs 

b) Corrosion of door sealing surfaces and 
studs 

c) Cracks 

d) Stretching or bending of the door stud or 
handhole door 

e) Looseness 



S1 .4.2.24 THREADED AND WELDED 
ATTACHMENT STUDS 

Threaded and welded attachment studs shal 
be inspected for: 

a) Corrosion, especially at the sheet 

b) Cracks 

c) Damaged threads 

d) Stretching or bending 

e) Looseness 

f) Leakage 



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NATIDNAL BOARD INSPECTION CODE • PART 2 — INSPECTION 



S1 .4.2.25 FUSIBLE PLUGS 

Fusible plugs shall be inspected for: 

a) Corrosion 

b) Scale buildup on the waterside 

c) Damage 

d) Tampering 

e) Leakage from the threads 

f) Height of the plug above waterside of 
crown sheet 

g) Evidence of melting or overheating 
h) Proper marking 



S1 .4.2.26 WATER CLASS, WATER 

COLUMN, AND GAGE COCKS 

The water glass, water column, and gage 
cock boiler connections and piping shall be 
inspected for: 

a) Mud and scale blockage 

b) Kinks or sharp, restricted or flattened bends 
in the piping 

c) Sags in the piping horizontal runs 

d) Condition of tubular or reflex water glass 

e) Correct type and material of piping and 
fittings 

f) Correct location, size, and installation of 
the connections to the sheets 

g) Correct installation of the safety shield (if 
used) 

h) Correct installation of the viewing light (if 
used) 



i) Correct installation of the test and drain 
valves 

j) Proper installation 

k) Proper bracing to prevent vibration 

I) Loose, bent or damaged nuts, bolts, and 
studs 

51 .4.2.27 STEAM PRESSURE GAGE 

The steam pressure gage, gage cock boiler con- 
nections, and piping shall be inspected for: 

a) Kinks or sharp, restricted or flattened bends 
in the piping 

b) Correct installation oftheshutoff valve and 
syphon 

c) Proper size, type, and material of piping 
and fittings 

d) Proper installation 

e) Proper lighting for viewing 

f) Proper bracing to prevent vibration 

g) Calibration 

51.4.2.28 BOILER FITTINGS AND PIPING 

The boiler fittings and associated piping shall 
be inspected for: 

a) Cracks 

b) Corrosion 

c) Pitting 

d) Leakage 

e) Looseness 



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NATIONAL BOARD INSPECTION CODE • PART 2 — INSPECTION 



f) Loose, bent or damaged nuts, bolts, and 
studs 

g) Adequate structural bracing, support, at- 
tachment, and provision for expansion 

h) Proper size, type, and material 



S1 .4.2.29 BOILER ATTACHMENT 
BRACKETS 

The boiler attachment brackets and associated 
components and fasteners used to secure the 
boiler to the frame shall be inspected for: 

a) Correct installation 

b) Damaged or missing components 

c) Looseness 

d) Leakage 

e) Loose, bent or damaged rivets, nuts, bolts 
and studs 

f) Defective rivets 

g) Provision for expansion 

S1 .4.2.30 FIRE DOOR 

The fire door, the locking mechanism, and the 
operating mechanism shall be inspected for: 

a) Safe and suitable operation 

b) Cracked, damaged, or burned parts 

c) Loose, damaged or bent rivets, nuts, bolts, 
and studs 

Note: The locking mechanism should be 
inspected for correct operation to confirm 
it will not allow the door to open in the 
event the firebox becomes pressurized. 



S1 .4.2.31 GRATES AND GRATE 

OPERATING MECHANISM 

The grates shall be inspected for: 

a) Cracked, damaged, burned, or missing seg- 
ments 

b) The grate operating mechanism of rocking 
grates shall be checked for: 

1) Uniform operation of all segments 

2) Corrosion 

3) Worn or cracked linkage 

4) Correct fit of the shaker bar on the link- 
age 

5) Missing pins or pin retainers 

6) Loose, bent or damaged nuts, bolts, and 
studs 

S1 .4.2.32 SMOKEBOX 

The smokebox shall be inspected for: 

a) Erosion 

b) Corrosion 

c) Leakage 

d) Holes 

e) Looseness 

f) Loose, bent or damaged nuts, bolts, and 
studs 



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NATIONAL BOARD INSPECTION CODE • PART Z 



INSPECTION 



51. 4.2.33 SMOKEBOX STEAM PIPES 

The smokebox steam pipes shall be inspected 
for: 

a) Erosion 

b) Corrosion 

c) Pitting 

d) Leakage 

e) Looseness 

f) Loose, bent or damaged nuts, bolts, and 
studs 

Note: Pitting from the casting process may 
be evident on cast thick wall steam pipes, 
but may not constitute a defect. 

51 .4.2.34 ASH PAN AND FIRE PAN 

The ash pan or fire pan shall be inspected for: 

a) Corrosion 

b) Holes 

c) Looseness 

d) Loose or damaged rivets, nuts, bolts, and 
studs 

e) Secure attachment to the frame or firebox 

f) Proper operation of the slides, clean out 
doors, dumping mechanism, and damp- 
ers 

g) Proper sealing of the slides, clean out doors, 
and dampers 



S1.5 GUIDELINES FOR STEAM 

LOCOMOTIVE STORAGE 

The steam locomotive guidelines published 
herein list the general recommendations for 
storage of locomotive boilers and locomotives. 
The exact procedures used by the owner/op- 
erator must be reviewed by the railroad me- 
chanical officers/engineers and be based on the 
conditions and facilities at the railroad shop or 
storage facility. 



S1.5.1 



STORAGE METHODS 



a) The methods for preparing a steam locomo- 
tive for storage depend upon several factors, 
including: 

1 ) the anticipated length of time the loco- 
motive will be stored; 

2) whether storage will be indoors or out- 
doors; 

3) anticipated weather conditions during 
the storage period; 

4) the availability of climate-controlled 
storage; 

5) type of fuel used; and 

6) equipment available at the storage 
site. 

b) Indoor storage can be categorized into 
two types: indoor with climate control and 
indoor without climate control. 

c) Outdoor storage can also be categorized 
into two types: outdoors during a warm 
time of year or in a geographic location 
where it can reasonably be expected to 
be above freezing during storage, and 
outdoors during a time period or in a geo- 
graphic location where it can be expected 
thatfreezing temperatures will occur during 
storage. 



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NATIONAL BOARD INSPECTION CODE • PART Z 



INSPECTION 



d) Locomotive boilers may be stored using the 
"wet method" or the "dry method." 

e) Before any method of storage, the boiler 
must be thoroughly washed out with mud 
and scale removed from the mudring, 
crownsheet, bottom of the barrel, and the 
top of the firing door. 



S1.5.2 



WET STORAGE METHOD 



a) When utilizing the "wet storage method" 
the boiler is completely filled with treated 
water to exclude air. 

Note: This method cannot be used if the 
locomotive is exposed to freezing weather 
during storage. 

b) Chemicals may be added to the storage 
water to further inhibit corrosion. How- 
ever, depending on the chemical used, the 
treated water may have to be disposed of as 
a hazardous waste to prevent chemical con- 
tamination of the surrounding property. 

c) The procedure applies only to the sections 
of the boiler that contain water. The firebox 
interior, cylinders, piping, and auxiliary 
equipment of the locomotive still require 
draining, preservation, and dry storage. 



S1.5.3 



DRY STORAGE METHOD 



When utilizing the "dry storage method" 
the boiler is completely emptied of water, 
dried out, and allowed to stand empty. 
Several variations of the "dry method" may 
be used. These include but are not limited 
to: 

1) air tight storage with moisture absor- 
bent placed in trays in the boiler; 

2) air tight storage with the boiler filled 
with inert gas to exclude oxygen; and 



3) open air storage with the mudring 
washout plugs removed to enable air 
circulation for evaporation of formed 
moisture. 

b) Each variation has positive and negative 
points that must be taken into account 
before use. If the boiler is filled with inert 
gas such as nitrogen, care must be taken 
because this method can result in asphyxi- 
ation of personnel if the gas escapes the 
boiler through a leaking valve or washout 
plug and enters a pit, sump, or enclosed 
room. In addition, the boiler must be com- 
pletely vented to remove gas, then tested 
and declared gas-free before personnel may 
enter. 

c) Although the use of dry storage with several 
washout plugs removed for air circulation is 
the most common method, there are some 
potential drawbacks. The boiler interior may 
be subject to moisture forming from con- 
densation created from humidity changes 
in the ambient air. Small animals may take 
up residence inside if screens are not used 
to cover handholes and washouts. 

d) Before storage, the boiler must be thorough- 
ly washed out with mud and scale removed 
from the mudring, crownsheet, bottom of 
the barrel, and top of the firing door. Any 
mud or loose scale left in the boiler will 
retain moisture leading to corrosion. After 
washing, water must be removed and the 
boiler dried before storage. A portable gas 
or electric heater placed in the firebox to 
aid evaporation and drying along with a 
vacuum used to siphon water out via the 
lower washout plugs is recommended. 

Note: Use of the common railroad drying 
out procedure of building a small wood fire 
in the firebox is not recommended because 
of the danger of overheating the firebox 
sheets. 

e) The typical railroad dry storage method re- 
quired blow down of the boiler until empty 



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NATIONAL BOARD INSPECTION CODE • PART 2 



INSPECTION 



while steam pressure registered on the gage 
and removal of the washout plugs while 
the shell plates were hot and there was 
no steam pressure. This allowed the heat 
remaining in the boiler plates to evaporate 
remaining water in the boiler. However, this 
method may result in staybolt damage from 
temperature change and requires extreme 
care, if used. 

f) Oil should not be applied to the interior 
surfaces of the boiler because it is difficult 
to remove. Further, the oil must be removed 
before steaming or it will form scale and 
contribute to foaming. 



S1.5.4 RECOMMENDED GENERAL 

PRESERVATION PROCEDURES 

a) When the locomotive is under steam, in- 
spect piping, fittings, and appliances for 
steam and water leaks that may introduce 
moisture into the lagging. Repair leaks as 
necessary and remove wet lagging. Wet 
lagging can accelerate corrosion of the 
boiler external surfaces, especially staybolt 
sleeves and caps. 

b) Thoroughly wash the boiler and firebox and 
remove mud and scale from the mudring, 
crownsheet, bottom of the barrel, and top of 
the firing door. Any mud or loose scale left 
in the boiler will retain moisture leading to 
corrosion. Wash out thermic siphons, arch 
tubes, and circulators. 



steam dome cover or top washout plugs 
should be removed to enable the moisture 
to escape. In addition, the driving wheels 
should be blocked and the throttle and cyl- 
inder cocks should be opened to permit any 
steam that forms in the superheater units to 
escape. 

d) Superheater units, by nature of design, can 
be difficult to drain and dry out. Typical 
methods include: 

1) Pressurize the boiler with compressed 
air with the locomotive stationary and 
blocked in place. Using the throttle to 
regulate the airflow, allow the air to 
blow through the entire bank of super- 
heater units and dry pipe and discharge 
into the cylinders. The cylinder cocks 
must be open. 

2) Pressurize the boiler with compressed 
air and then operate the locomotive 
under air pressure over a short distance 
of track. The cylinder cocks should be 
opened during the initial operation 
to prevent damaging the cylipders by 
hydraulic lock. 

3) If the air pressure draining procedure 
is not practical or cannot be accom- 
plished correctly, the superheater units 
can be protected against trapped mois- 
ture by filling the entire superheater 
bundle with a standard antifreeze/water 
mixture or with diesel fuel. 



c) To protect the boiler interior during stor- 
age, dry the boiler by using compressed 
air to blow out as much water as possible. 
A portable heater placed in the firebox to 
warm the boiler to 200°F (93°C) along with 
a vacuum used to siphon water out via the 
lower washout plugs can aid evaporation 
and drying of any moisture that collects in 
low or impossible-to-drain locations with- 
out harming the sheets. 

Caution: To prevent a build up of steam 
pressure during the drying process, the 



Notes: The air pressure dry-out methods 
"1 " or "2" may have to be performed 
several times to discharge all of the 
moisture. Refer to S1 .5.5, Use of Com- 
pressed Air to Drain Locomotive Com- 
ponents, for additional information on 
compressed air drying. 

If the locomotive is operated under air 
pressure, the air brake system should 
be made operational to provide safe 
stopping or other steps taken to control 
and stop the locomotive. 



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NATIONAL BOARD INSPECTION CODE • PART Z 



INSPECTION 



e) After drying, it will be necessary to either 
vent the boi ler or to place containers of des- 
iccant inside the boiler through the dome 
cap to absorb any condensation that may 
occur during storage. Venting the boiler to 
allow air circulation is accomplished by 
leaving two or more of the lower washout 
plugs out and opening the vent valve on 
the top of the boiler. A vent line consisting 
of two 90° elbows and pipe nipples should 
be installed in the vent valve to locate the 
opening to the downward direction in order 
to keep rain or snow from entering the open 
valve. 

f) If the locomotive will be stored outdoors, 
the following should be completed: 

1) Inspect the boiler jacket and confirm 
it is tight with no gaps leading into the 
lagging or shell. Pay close attention 
to areas at shell openings such as for 
studs, safety valves, etc. Repair all gaps 
or damaged jacket sections as neces- 
sary. Consideration should be given 
to covering the entire locomotive and 
tender with atarp. Otherwise, all jacket 
openings should be covered to prevent 
the entrance of rain or snow. Where 
necessary, apply a waterproof covering 
over the exposed or open sections. 

2) The smokestack should be sealed by ap- 
plying a wood and sheet rubber cover 
held in place by clamps or a through 
bolt. 

3) The safety valves should either be cov- 
ered or removed, with plugs or caps 
installed in the holes if the valves are 
removed. 

4) The dynamo, air pump, and feedwater 
heater exhausts should also be cov- 
ered. 

5) Empty and clean the smokebox, front 
tube sheet, superheater units, steam 
pipes, and front end plates of all coal, 



ash, or burntoil. This work is especially 
critical at the bottom section of the 
smokebox and front tubesheet rivet 
flange. The smokebox door should be 
sealed by applying a gasket or seal- 
ant and any other air openings in the 
smokebox sealed. The exhaust nozzle 
should be sealed by applying a wood 
and sheet rubber cover held in place 
by clamps. 

6) The potential for corrosion of the 
smokebox interior can be further mini- 
mized by applying coating of outdoor 
paint or primer. All inspection of the 
smokebox and front tubesheet must be 
accomplished before painting since it 
will cover up many types of defects. The 
coating will burn off quickly when the 
locomotive is returned to service. 

7) Thoroughly clean the firebox sheets, 
flues, and superheater return bends of 
all ash and clinker. 

8) On coal burners, empty and clean the 
grates and ash pan of all coal and ash 
completely. This work is especially criti- 
cal at the sections between the grate 
bearers, the mudring rivets, and firebox 
sheets; and from the grate segment air 
openings. On oil burners, care should 
be taken to remove ash from between 
the flash wall refractory and the firebox 
sheets. 

9) If the locomotive will be out of service 
for longer than 12 months, removal of 
the brick arch or flash wall refractory 
that extends above the mudring should 
be considered to prevent condensation 
and corrosion from occurring between 
the brick and the steel. Temporary re- 
moval of the brick arch or flash wall 
to permit application of a preservative 
to firebox sides, arch tubes, or siphons 
should be considered for shorter storage 
periods. 



1 2D 



NATIONAL BOARD INSPECTION CODE • PART 2 



INSPECTION 



10) All appliances and piping that might 
contain water or condensation should 
be drained and blown dry using dry 
compressed air. This includes the air 
and equalizing reservoirs, dirt collec- 
tors, injectors, cylinders, stoker engine 
cylinders, dynamos, the steam and 
water sides of feedwater heaters and 
pumps, the steam side of air pumps, the 
steam side of lubricators, atomizers, oil g) 
tank heaters, gage siphons, tank hoses, 

and cab heater piping. A small quan- 
tity of valve oil should be sprayed into 
the valve chambers, cylinders and the 
steam side of all appliances to protect 
against corrosion. Refer to S1 .5.5, Use 
of Compressed Air To Drain Locomotive 
Components, for details. h) 

1 1 ) The cylinder castings, exhaust cavities, 
and steam lines must be drained of all 
moisture and blown dry. Typical meth- 
ods include: 

a. Pressurize the boiler with com- 
pressed air with the locomotive sta- i) 
tionary and blocked in place. Using 

the throttle to regulate the airflow, 
allow the air to blow through the 
dry pipe and discharge into the 
cylinders. The cylinder cocks must 
be open. 

b. Pressurize the boiler with com- 
pressed air then operate the loco- 
motive under air pressure over a j) 
short distance of track. The cylinder 
cocks should be opened during the 
initial operation to prevent dam- 
aging the cylinders by hydraulic 
lock. 

Note: Methods "1 " or "2" may have 
to be performed several times to 
discharge all of the moisture from 
the cylinders and steam pipes. If 
the locomotive is operated under k) 
air pressure, the air brake system 



should be made operational to 
provide safe stopping or other steps 
taken to control and stop the loco- 
motive. 

c. Refer to S1 .5.5, Use of Compressed 
Air to Drain Locomotive Compo- 
nents, for additional information. 

Drain and wash tender water spaces. The 
tank should be inspected afterward and 
any remaining water removed by syphon or 
vacuum. When dry, spray the water space 
with outdoor paint or a commercial rust 
preventative. Drain and dry tender tank 
hoses and clean screens. 

On coal or wood burners, spray any ex- 
posed surfaces of the tender fuel space 
with outdoor paint or a commercial rust 
preventative. If the locomotive is to be 
stored outdoors for long term, remove all 
coal and spray the surfaces as above or 
cover the coal space with a tarp or a roof. 

On oil burners, drain and blow out all fuel 
lines, tank heater and blowback lines, and 
the burner itself. Drain sludge and water 
from the bottom of the fuel tank. Ensure 
that tank hatches are secure and the tank is 
vented to prevent condensation. Draining 
the oil tank is recommended if the fuel oil 
is known to lose its volatile content during 
storage. 

After cleaning thoroughly, coat all side and 
main rods, cross heads, valve gear, guides, 
piston rods, brake pistons, feedwater pump 
pistons, and air pump pistons with water-re- 
sistant grease or a rust preventative. Grease 
should be applied to the junction of each 
axle and driving box and journal box to 
prevent water entering. Grease should be 
applied to junction of rod and pin in valve 
gear and rods to prevent water entering. 

If the locomotive is moved after this is ap- 
plied, it will be necessary to reapply the 
coating to piston rods and guides. 



1 2 1 



NATIDNAL BOARD INSPECTION CODE • PART 2 — INSPECTION 



m 



Note: Heavy oil or unrefined oil such as 
any of the Bunker types (Bunker 6, etc.) 
should not be used for preservation of any 
components because the sulfur contained 
in it can accelerate corrosion. Standard 
motor oil or journal oil will not stick to 
and preserve wetted surfaces. All surfaces, 
to be so coated, must be dry. If moisture 
is a problem, steam cylinder oil should be 
applied. 

Plain journal bearings should be inspected 
for water and repacked. Roller bearing 
boxes should have all moisture drained 
and the boxes filled with lubricant. Grease 
plugs should be screwed down so that the 
threads are not exposed. 

If the locomotive is to be stored outdoors 
with questionable or no security, remove 
and store all cab gages, water glasses, lu- 
bricators, brass handles, seatboxes, and any 
other items that thieves or vandals might 
attack. Remove the whistle, bell, headlight, 
and marker, and/or classification lights. Re- 
move tools, radios, and spare parts. Secure 
wood or metal covers over all windows 
and doors, and board up the back of the 
cab. Secure all manholes on the top of the 
tender. 

Inspect stored locomotives regularly for 
signs of rust, corrosion, damage, deterio- 
ration, or vandalism and immediately take 
any corrective measures necessary. 



b) The air compressor must be equipped with 
a suitable filter to enable it to supply oil- 
free air because the introduction of air that 
contains oil into the water/steam parts of 
the boi ler and superheater wi 1 1 promote the 
formation of scale and water foaming when 
the locomotive is returned to service. 

c) The air compressor must be a large enough 
size to provide the volume and pressure of 
air required. 

d) If the boiler is pressurized with compressed 
air, the air pressure must be raised slowly 
to prevent distorting or overstressing the 
firebox sheets or staybolts because the 
normal expansion of the boiler that occurs 
under steam pressure is not present when 
air pressure is used. 

e) Auxiliary components such as the stokers, 
air compressors, turbo generators, power 
reverse are drained by pressurizing the 
boiler to between 1/2 to 3/4 of the rated 
boiler pressure with compressed air from 
the stationary air compressor, then operat- 
ing each component individually until the 
exhaust from it contains no moisture. 

f) When necessary, specific pipe lines can be 
drained by breaking the line at each end, 
attaching the air line to it directly then 
blowing the line out. 



S1.5.6 



RETURN TO SERVICE 



S1.5.5 USE OF COMPRESSED AIR 

TO DRAIN LOCOMOTIVE 
COMPONENTS 

a) The process of using air pressure to drain 
and empty auxiliary components such as 
the cylinders, superheater units, and piping 
completely of water offers several advan- 
tages over other methods. 



When returning a locomotive to service, 
the boiler, firebox, and tender tank shall 
be ventilated to remove potentially haz- 
ardous atmosphere from the boiler interior 
before personnel enter it. In addition, the 
atmosphere in the boiler shall be verified 
to be safe for human occupancy before 
personnel enter it. For the boiler this can 
be accomplished by removing the washout 



1 22 



NATIONAL BOARD INSPECTION CODE • PART Z — INSPECTION 

plugs and placing a fan or air blower on 
top of the steam dome opening to force air 
into the boiler. For the firebox this can be 
accomplished by opening the smokebox 
door and firebox door and placing a fan 
or air blower at either location to force air 
through. Failure to do this could result in 
asphyxiation of the personnel entering the 
boiler or firebox. 

b) If possible, the locomotive should be moved 
into a heated engine house and the boiler 
allowed to warm up in the air for several 
days until it is the same temperature as the 
air. 

c) The initial fire up should be done slowly to 
allow even heating of the boiler. 

d) Before movement, the cylinders should be 
warmed up by allowing a small quantity 
of steam to blow through them and out the 
cylinder cocks and exhaust passages. This is 
necessary to reduce the stress in the casting 
from thermal expansion of the metal. 

e) Steam should be discharged through the 
cylinder cocks for several minutes to aid 
removal of any solvent, debris, or rust that 
may have formed in the superheater units, 
steam pipes, and dry pipe. 

f) All appliances should be tested under steam 
pressure before the locomotive is moved. 



1 23 



NATIONAL BOARD INSPECTION CODE • PART 2 



INSPECTION 



SUPPLEMENT 2 

HISTORICAL BOILERS 



S2.1 



SCOPE 



b) 



This supplement is provided as a guide to 
inspection of historical steam boilers of 
riveted and/or welded construction not fall- 
ing under the scope of Supplement 1 . These 
historical steam boilers would include: 
steam tractors, traction engines, hobby 
steam boilers, portable steam boilers, and 
other such boilers that are being preserved, 
restored, and maintained for demonstra- 
tion, viewing, or educational purposes. 

Note: This supplement is not to be used 
for steam locomotive boilers falling under 
the requirements of the Federal Railroad 
Administration (FRA). FRA rules for steam 
locomotive boilers are published in 49 CFR 
230. Specific rules and special require- 
ments for inspection, repairs, alterations, 
and storage of steam locomotive boilers are 
identified in Supplement 1 of the NBIC. 

The rules specified in this supplement shall 
be used in conjunction with the applicable 
rules in this Code. References specified or 
contained in this Supplement may provide 
additional information to assist the user 
when applying the requirements of this 
supplement. 



S2.2 



INTRODUCTION 



a) The following inspection rules are mini- 
mum requirements for safe and satisfactory 
operation of historical boilers. Users of 
this supplement are cautioned that where 
complete details are not provided, the user 
is advised to seek technical guidance to 
provide good sound engineering evalua- 
tions and practices. 

b) Where adopted by a Jurisdiction, these 
requirements are mandatory. Where a Ju- 



risdiction establishes different requirements 
for historical boilers or where a conflict 
exists, the rules of the Jurisdiction prevail. 



S2.3 



RESPONSIBILITIES 



The owner-user and/or operator are responsible 
for ensuring that the boiler meets the require- 
ments of the Jurisdiction where the boiler 
is operated, including inspections, repairs, 
licensing, operating certificates, permits, and 
operator training. 

Note: It should be recognized that safety of 
these boilers is dependent upon the knowledge 
and training of the operator in proper use, re- 
pair, maintenance, and safe operation of each 
specific boiler proposed to be operated. (See 
S2.4.3) 



S2.4 GENERAL INSPECTION 

REQUIREMENTS 

The owner-user and Inspector should refer to 
1 .4 Personnel Safety, Section 3 of this Part, Cor- 
rosion and Failure Mechanisms, and Section 4 
of this Part, Examinations, Test Methods, and 
Evaluations, for additional information when 
performing inspections. 



S2.4.1 PRE-SNSPECTION 

REQUIREMENTS 

a) The owner or user has the responsibility to 
prepare the boiler for any required inspec- 
tions needed to assure safety as deemed 
necessary by the I nspector. Prior to perform- 
ing any type of inspection, the owner and 
Inspector shall assure safety precautions are 
taken to prevent personal injury. 

b) Prior to conducting an inspection, the fol- 
lowing shall be reviewed by the Inspector 
to the extent possible to aid in determining 
safe operation: 



1 24 



NATIONAL BOARD INSPECTION CODE • PART 2 — INSPECTION 



1) Operating and maintenance history 
and/or other information contained in 
the Operator Log Book; 



Inspection history; 

Construction Code/Design; 

Materials — types and thickness; 

Certifications; 

Operator knowledge and training as 
required by the Jurisdiction; 

Repairs/Alterations performed; 

Cleanliness of the boiler; and 

Potential hazards to personnel. 

Note: If a boiler has not been properly 
prepared for an inspection, the Inspec- 
tor may decline to make the inspec- 
tion. 

POST-INSPECTION ACTIVITIES 



S2.4.2 



a) Upon completion of inspection activities, 
the results of examinations and tests shall 
be documented by an Inspector, in a man- 
ner acceptable to the Jurisdiction. 

b) Any defects or deficiencies in the condition, 
operation, and/or maintenance practice 
of the boiler and appurtenances shall be 
discussed and documented with the owner 
and/or user. Recommendations for correc- 
tion and/or repair requirements (if required) 
shall be discussed and documented. 



S2.4.3 



BOILER OPERATORS 



inspection and testing for each boiler pro- 
posed to be operated: 

1) Jurisdictional rules for construction, 
maintenance, repairs, operation, and 
certification. 

2) Boiler functions and purpose of con- 
trols, appurtenances, and safety de- 
vices. 

3) Proper operation, maintenance, types, 
use and testing of valves including 
safety valves. 

4) Fusible plugs including installation, 
maintenance, design, and purpose. 

5) Performance of normal and emergency 
system operating procedures associated 
with blowdown of the boiler, feed, or 
water delivery system, steam system, 
water level control, and combustion of 
fuel. 

6) Importance of maintenance, cleaning, 
and inspection of components and 
safety devices such as pressure gages, 
sight glass, governor, water column, 
firebox, etc. 

7) Preparation and actions to be taken on 
emergency situations for fire, low water, 
foaming, overpressure, and excessive 
leakage. 

b) Organizations/associations involved with 
historical boilers should verify operator 
knowledge by examination or practical 
testing or a combination of both. Some 
Jurisdictions may require specific operator 
qualifications or certifications. (See addi- 
tional safety procedures in S2.14). 



The following guidelines should be under- 
stood by each historical boiler operator and 
demonstrated safely during jurisdictional 



1 25 



NATIONAL BOARD INSPECTION CODE • PART 2 — INSPECTION 



S2.4.4 



EXAMINATIONS AND TESTS 



The examinations and tests shall be as re- 
quired by the Jurisdiction and verified by an 
Inspector. The Inspector shall accept and verify 
procedures and personnel qualifications when 
examinations and tests are performed. 



S2.4.4.1 NONDESTRUCTIVE 

EXAMINATION METHODS 

There are a variety of nondestructive examina- 
tion methods that may be employed to assess 
the condition of historical boilers. Skill, expe- 
rience, and integrity of personnel performing 
examinations are essential to obtaining mean- 
ingful results. Generally, some form of surface 
preparation will be required prior to the use of 
examination methods. 



S2.4.4.2 TESTING METHODS 

Testing should be performed by experienced 
personnel using procedures acceptable to the 
Inspector. Typical test methods available to the 
Inspector during the inspection of historical 
boilers are listed below: 

a) Hydrostatic testing/pressure testing; 

b) Leak testing; and 

c) Ultrasonic thickness testing. 



S2.5 SPECIFIC EXAMINATION AND 

TEST METHODS 



S2.5.1 SPECIFIC EXAMINATION 

METHODS 

a) This part describes nondestructive exami- 
nation and test methods that are typically 
available to the Inspector during inspection 
of historical boilers. 

1) Visual (VT) 



b) 



2) Ultrasonic (UT) 

3) Liquid Penetrant (PT) 

4) Magnetic Particle (MT) 

5) Radiographic (RT) 

Additional examination or test methods 
may be performed if a deficiency is de- 
tected during initial or reoccurring inspec- 
tion. Use of additional examination and 
testing methods shall be acceptable to the 
Inspector and the Jurisdiction, if required. 



S2.5.2 



VISUAL EXAMINATION 



Visual examination is the most widely used 
method to ascertain surface condition and 
recognize surface features typical of various 
damage mechanisms associated with historical 
boilers. Damage mechanisms such as corrosion 
or cracking may be due to operation, age of 
material, or improper maintenance. 



S2.5.2.1 PREPARATION FOR VISUAL 
INSPECTION 

The owner-user shall ensure the following areas 
as a minimum are prepared for visual examina- 
tion, and is acceptable to the Inspector at the 
time of the examination. 

a) Fireside open and grates removed 

b) Fireside tubesheets and tubes thoroughly 
cleaned of soot and ash 

c) Waterside drained and hand holes, plugs, 
and inspection openings removed 

d) Sediment, scale, and mud flushed 

e) Insulation or jackets removed as appropriate 

Note: Where there is limited or no access 
for visual inspection, remote camera or 
fiber optic devices may be used. 



1 26 



NATIONAL BOARD INSPECTION CODE • PART 2 



INSPECTION 



S2.5.2.2 VISUAL EXAMINATION 
REQUIREMENTS 

To the extent possible, the following areas 
and items shall be visually examined by the 
Inspector and results documented on the boiler 
inspection guideline (S2.11) provided in this 
supplement, or as required by the Jurisdiction. 
Use of the boiler inspection guideline should 
be used as a reference when performing visual 
inspections. 

a) The fusible plugs shall be removed, inspect- 
ed, and confirmed to meet requirements 
ofS2.8.4. 

b) Threaded openings or connections in the 
boiler shall be inspected for wear or dete- 
rioration when there is evidence of leakage. 
ANSI standard plug and ring gages may be 
used to verify thread integrity. 

c) Inspectthe condition of boiler sheets, shell, 
tubesheets, fittings, staybolts, and other 
materials for thinning, pitting, cracks, or 
corrosion. 

d) Verify that requirements of S2.8 through 
S2.9 are in compliance, as applicable. 



S2.5.3 



ULTRASONIC EXAMINATION 



Ultrasonic examination is used as a volumet- 
ric examination of welds and base materials 
for detection of flaws. Factors such as mate- 
rial composition, surface condition, choice of 
equipment, and ability of the operator affect 
the results of ultrasonic examination. 



S2.5.4 LIQUID PENETRANT 

EXAMINATION 

Liquid penetrant examination is used to detect 
discontinuities open to the surface such as 
cracks, seams, laps, cold shuts, laminations, 
and porosity. 



S2.5.5 MAGNETIC PARTICLE 

EXAMINATION 

Magnetic particle examination can be used to 
reveal surface discontinuities and to a limited 
degree discontinuities slightly below the sur- 
face. The sensitivity of this method decreases 
rapidly with depth below the surface and 
therefore is used primarily to examine surface 
discontinuities. 



S2.6 



SPECIFIC TESTING METHODS 



During inspection of historical boilers there 
may be instances where conditions have ad- 
versely affected the tightness of the boiler or 
the inspection discloses hard to evaluate forms 
of deterioration that may affect the safety of 
the vessel. In these specific instances, a pres- 
sure test using water or other suitable liquid 
test medium may be required at the discretion 
of the Inspector to assess leak tightness of the 
pressure-retaining item. For safety, pneumatic 
pressure tests shall not be performed. 



S2.6.1 HYDROSTATIC PRESSURE 

TESTING 

When performing hydrostatic pressure test- 
ing for verification of leak tightness or when 
required by the Jurisdiction, the following 
requirements shall be met: 

a) Hydrostatic pressure test shall be between 
the calculated maximum allowable work- 
ing pressure and 1 .25 times the calculated 
maximum allowable working pressure, 
and held for a minimum of 10 minutes or 
as required to perform a complete visual 
examination. 

b) The metal and water temperature of the 
boiler shal I be between 60°F to 1 20°F (1 6°C 
to 49°C) anytime a hydrostatic test is being 
performed. 



1 27 



NATIDNAL BOARD INSPECTION CODE • PART 2 



INSPECTION 



c) A calibrated gage acceptable to the Inspec- 
tor shall be used when hydrostatically pres- 
sure testing a boiler. 

d) During hydrostatic testing, safety valve(s) 
shall be removed. 



S2.6.2 ULTRASONIC THICKNESS 

TESTING 

Ultrasonic thickness (UT) testing shall be per- 
formed to determine boiler plate thickness. 
UT testing shall be performed by personnel, 
acceptable to the Jurisdiction and the Inspector. 
The following requirements shall be met to the 
extent possible. Performance and results shall 
be acceptable to the Inspector and, if required, 
the Jurisdiction. 

a) Equipment, operator, and calibration stan- 
dards used shall be documented. 

b) To calculate MAWP, ultrasonic thickness 
testing results in areas of generalized thin- 
ning (3 in. [76 mm] in diameter or greater) 
or where grooved thinning is noted (2 in. 
[50 mm] in length or greater) are to be used 
in determining minimum thickness in ac- 
cordance with S2.10. The MAWP calcula- 
tion in S2.1 shall be completed based on 
the thickness data gathered. 

c) On initial UT of stayed sections, the plate 
thickness readings should be taken on a grid 
not exceeding the maximum staybolt pitch. 
Additional readings may be taken close 
to each staybolt to determine if localized 
thinning has occurred. Particular attention 
should be given to the joint between the 
staybolt and the plate. 

d) On initial UT of unstayed sections, the plate 
thickness readings should be taken on a 
grid not exceeding 12 inch (300mm) cen- 
ters. Additional readings should be taken if 
conditions warrant. 

e) UT test results shall be documented so 
location of test results can be checked at 



subsequent UT tests to determine if material 
loss has occurred. 

Recurring UT testing shall be performed 
by randomly checking 1 0% of original UT 
checks. Areas of thinning identified during 
previous inspections shall be given particu- 
lar attention. If material loss is determined, 
additional testing may be requested by the 
Inspector. 

The owner/operator shall maintain the 
initial and recurring grid mapped UT read- 
ings in conjunction with the calculations in 
permanent boiler records. Documentation 
shall be available to the Inspector for review 
and acceptance. 



S2.7 



INSPECTIONS 



The requirements of this section shall be used 
in conjunction with the general requirements 
identified in S2.4. 



S2.7.1 



INSERVICE INSPECTIONS 



The following examinations and tests shall be 
performed while the boiler is in operation: 

a) Two independent means of boiler feed 
water delivery systems shall be demon- 
strated to the Inspector. Observance to be 
performed at an operating pressure no less 
than 90% of the safety valve set point of the 
boiler. If the boiler is equipped with more 
than one feedwater tank, each feedwater 
device must be able to take water out of 
either feedwater tank. Pumped feedwater 
shall be preheated prior to entering the 
boiler. 

b) Demonstration of operable try cocks that 
show a level of water that correlates with 
that shown in the gage glass. 

c) Demonstration of operating gage glass up- 
per and lower shutoff valves. 



i zs 



NATIONAL BOARD INSPECTION CODE • PART 2 — INSPECTION 



d) Demonstration of an operating gage glass 
blowdown valve. 

e) Check that the gage glass is visually clear 
and fully operational. 

f) Visual inspection for leaks. 

g) Safety valves shall be tested by having the 
operator raise boiler pressure to the safety 
valve popping point. Popping point pres- 
sure and blowdown will be observed to 
ensure they are within tolerances (see S2.8). 
Alternatively, a certification acceptable to 
the Jurisdiction maybe used for verification 
of set pressures. 



S2.7.2 INSERVICE INSPECTION 

DOCUMENTATION 

Inservice inspection shall be documented as 
required by the Jurisdiction where the boiler 
is operated, or Form NB-5 or similarMbrm may 
be used. 



S2.7.3 



INSPECTION INTERVALS 



S2.7.3.1 INITIAL INSPECTION 

a) Initial inspections shall be performed to 
determine baseline criteria needed for the 
operating life of the boiler. The owner-user 
shall maintain documentation and inspec- 
tion results as required by this section. In 
addition to the required Jurisdiction inser- 
vice inspection report identified in S2.7.2, 
Form C-1 (See S2.12) may be used for the 
documentation of initial examinations and 
inspections. 

b) Boilers initially evaluated in accordance 
with this inspection code shall be subject 
to the following examinations and tests: 

1) A visual internal examination per 
S2.5.2; 



2) A visual inservice examination per 
S2.7.1; ■ 

3) Initial UT test requirements per 
S2.6.2; 

4) MAWP calculation per S2.10; 

5) Hydrostatic Pressure Testing per S2.6.1 ; 
and 

6) Other examinations (UT, PT, MT) as 
required by the Jurisdiction or Inspector 
to determine boiler integrity. 



S2.7.3.2 SUBSEQUENT INSPECTIONS 

a) Boilers that have completed the initial 
inspection requirements begin the subse- 
quent inspection intervals. The following 
inspection intervals should be used unless 
other requirements are mandated by the 
Jurisdiction. 

1) Interval #1 — one year following initial 
inspection. Inservice inspection per 

S2.7.1. 

2) Interval #2 — two years following ini- 
tial inspection. Visual inspection per 

S2.5.2.2. 

3) Interval #3 — three years following 
initial inspection. A pressure test per 
S2.6.1. 

4) Interval #4 — same as interval #1 . 

5) Interval #5 — Visual inspection per 
S2.5.2.2 and UT thickness testing per 
S2.6.2. 

6) Interval #6 — same as interval #3. 

b) After interval #6 is completed, the sub- 
sequent inspection cycle continues with 
interval #1 . 



1 29 



NATIONAL BOARD INSPECTION CODE • PART 2 



INSPECTION 



S2.8 SAFETY DEVICES 

REQUIREMENTS 



GENERAL 



Each boiler shall be equipped with the follow- 
ing safety devices: safety valve(s), gage glass(s), 
try-cock(s), fusible plug(s), and pressure gage(s). 
These safety devices shall be verified by the 
owner and inspector and documented on the 
Boiler Inspection Guide S2.1 1 for proper instal- 
lation and purpose during each inspection. 



ity should be avoided. (Only heating 
surface area above the grates shall be 
used when calculating heating surface 
for safety valve required capacity.) 

Note: An additional pressure relief 
valve may be used in conjunction with 
the above required ASME safety valve 
if set at a lower pressure, although no 
credit for relieving capacity may be 
used. 



S2.8.1 



SAFETY VALVES 



The following requirements shall be verified 
acceptable when performing inspections of 
safety valves. 

1) Set pressures of safety valves installed 
shall be verified by operation or certi- 
fication acceptable to the Jurisdiction. 

2) Safety valve(s) shall be National Board 
capacity certified. 

3) Safety valve(s) shall be sealed by an 
ASME "V" Stamp holder or NB "VR" 
repair firm. 

4) The required safety valve capacity in 
pounds per hour (kg per hour) shall 
be calculated by multiplying boiler 
heating surface area by the type of fuel 
factor used (see Table S2.8.1 for fuel 
factors). Excessive safety valve capac- 



5) Safety valve(s) shall have a test lever. 

6) No isolation valve of any description 
shall be placed between the required 
safety valve(s) and the boiler, or on the 
discharge pipe between the valve and 
the atmosphere. 

7) The piping connection between the 
boiler and the safety valve shall not 
be less than the inlet size of the safety 
valve, and the discharge pipe, if used, 
shall not be reduced between the safety 
valve and the point of discharge. 

b) To reduce cycling stress on the boiler, it is 
recommended that a safety valve with a 
blowdown between 2% and 4% is used. 
The blowdown, however, should never 
exceed 6%. 



TABLE S2.8.1 

Minimum Pounds of Steam per Hour per Square Foot of 

Heating Surface (1 lb. Steam/hr./sq. ft. [4.88 kg/hr./sq. m]) 


Boiler Heating Surface 


Firetube Boilers 


Watertube Boilers 


Hand-Fired 


5 


6 


Stoker-Fired 


7 


8 


Power Burner 


8 


10 


Hand-Fired Waterwall 


8 


8 


Stoker Waterwall 


10 


12 


Power Burner Waterwall 


14 


16 





1 3D 



NATIONAL BOARD INSPECTION CODE • PART 2 — INSPECTION 



S2.8.2 



GAGE GLASS 



Historical boilers shall be equipped with at 
least one gage glass meeting the following 
requirements: 

a) The gage glass shall be fitted with a guard 
to protect the glass. 

b) The gage glass shall indicate the minimum 
safe operating water level. 

c) The gage glass shall be provided with a drain 
valve or petcock, piped to a safe location. 

d) The gage glass shall be visually clear and 
fully operational. 

e) The distance from the highest point on the 
crown sheet to the top of the lowest pack- 
ing nut of the gage glass should be checked 
and documented. 



S2.8.3 



TRY-COCKS 



Historical boilers shall be equipped with try 
cocks meeting the following requirements: 

a) Try cocks shall be correctly located in 
reference to the minimum required water 
level. 

b) Try cocks shall be open (unplugged) and 
fully operational. 

c) If the boiler was not originally fitted with try 
cocks, a newly installed try cock shall be 
located 3 inches above the crownsheet. 



b) Boilers shall have a fusible plug unless 
equipped and operated with automatic 
controls. 

c) Fusible plugs shall be constructed to meet 
the requirements of the ASME Code, and 
indicated as such by the ASME marking on 
the filler material. 

d) Fireside fusible plugs must protrude a mini- 
mum of 3/4 inch (1 9 mm) into the water. 

e) Fusible plugs may not protrude into the fire 
area more than 1 inch (25 mm). 

f) Fusible plugs shall not be refilled. 

g) Fusible plugs shall be replaced on initial 
jurisdictional inspection and after 500 
hours of service, if hour of service can 
be proven, If hours of service can not be 
proven they shall be replaced every three 
calendar years. Fusible plug life shall not 
exceed ten calendar years. 

h) Leaking fusible plugs shall be replaced. 



S2.8.5 



PRESSURE GAGE 



S2.8.4 



FUSIBLE PLUG 



Historical boilers shall be equipped with at 
least one pressure gage meeting the following 
requirements: 

a) Tested and proven accurate within plus or 
minus 5 psi (35 kPa) of the safety valve set 
point at the time of the inservice inspection 
pressure test. If the gage is found to be out 
of this specified range it shall be calibrated 
to a national standard using a master gage 
or dead weight tester traceable to a national 
standard. 



Historical boilers equipped with fusible plugs 
shall meet the following requirements: 

a) The fusible plug shall be inspected to de- 
termine the condition of the threads in the 
crown sheet and on the fusible plug. 



b) Siphon, or water seal, shall be installed 
between pressure gage and boiler. 

c) If a valve is installed between the gage and 
the boiler, the valve shall indicate the open 
position or be sealed open. 



1 3 i 



NATIONAL BOARD INSPECTION CODE • PART 2 



INSPECTION 



d) The range of pressure gage shall be 1 .5 to 
3.5 times the set point of the safety valve. 



S2.9 APPURTENANCES — PIPING, 

FITTINGS, AND VALVES 

Boiler piping and fittings shall meet the follow- 
ing requirements: 

a) Threaded openings shall follow accepted 
standard piping practices and ANSI general 
pipe thread requirements. 

b) Schedule 80, black pipe (SA-53 CR. A or B 
types ERW or Seamless; SA-1 06 GR.A,B,C) 
shall be used for boiler pressure piping. 
Galvanized pipe and fittings and A-53 Type 
F and API-5L Grade A 25 pipe are prohib- 
ited on boiler pressure piping. 

c) Steam piping components shall be used in 
the manner for which they were designed 
and shall not exceed manufacturer's pres- 
sure rating. Malleable iron Class 300 
threaded fittings per ASME B16.3 are ac- 
ceptable for use. The use of malleable iron 
class 150 is not recommended. Forged 
threaded fittings per ASME B1 6.1 1 classes 
2000-6000 are acceptable for use. 

d) The blowdown line shall be piped to a safe 
point of discharge during the time the boiler 
is operating. 

e) Piping shall be properly supported. 

f) Valves shall be used in the manner for 
which they were designed, and shall be 
used within the specified pressure-tem- 
perature ratings. Valves shall be rated at 
or above the pressure setting of the boiler 
safety valve, denoted by the general or 
primary pressure class identification on the 
valve body and/or by the initials "WSP" or 
"S" to indicate working steam pressure or 



steam rating. Valves in cold water service 
may be designated by the initials "WOG" 
to indicate water, oil, or gas rating and/or 
by the pressure class identification on the 
valve body. 

The boiler shall be equipped with two 
means of supplying feedwater while the 
boiler is under pressure. 



S2.9.1 PIPING, FITTINGS, AND VALVE 

REPLACEMENTS 

The installation date should be stamped or 
stenciled on the replaced boiler piping. Alterna- 
tively, the installation date may be documented 
in permanent boiler records, such as the opera- 
tor log book. 



S2.10 MAXIMUM ALLOWABLE 

WORKING PRESSURE (MAWP) 

Note: The rules of ASME Section I 1971 Edi- 
tion, Part "PR" and "PFT" may be used for 
determining specific requirements of design 
and construction of boilers and parts fabricated 
by riveting. 2 

The MAWP of a boiler shall be determined by 
computing the strength of each boiler compo- 
nent. The computed strength of the weakest 
component using the factor of safety allowed 
by these rules shall determine the MAWP. 



S2.10.1 STRENGTH 

a) In calculating the MAWP, when the ten- 
sile strength of the steel or wrought iron 
is known, that value shall be used. When 
the tensile strength of the steel or wrought 
iron is not known, the values to be used 
are 55,000 psi (379 MPa) for steel and 
45,000 psi (310 MPa) for wrought iron. 



2 Copies of ASME Section I 1971 Edition Part "PR" and 
"PFT" referenced section may be obtained by contacting the 
National Board of Boiler and Pressure Vessels, 1055 Crupper 
Ave., Columbus, OH 43229. 



1 32 



NATIONAL BOARD INSPECTION CODE • PART 2 — INSPECTION 



Original steel stamp marks, original mate- 
rial certifications, or current laboratory tests 
are acceptable sources for verification of 
tensile strength. Catalogs and advertising 
literature are not acceptable sources for 
tensile strength values. 

b) In computing the ultimate strength of riv- 
ets in shear, the following values shall be 
used: 

1) Iron rivets in single shear 
38,000 psi (262 MPa) 



strength of the plate, the efficiency of the lon- 
gitudinal joint, the inside diameter of weakest 
course, and the design margin allowed by 
these rules using the following formula orTables 
S2.10.3.1 through S2. 10.3. 6: 



MAWP 



TS x t x E 
RxFS 



See definitions of nomenclature in S2.1 0.6. 



2) Iron rivets in double shear 
76,000 psi (524 MPa) 

3) Steel rivets in single shear 
44,000 psi (303 MPa) 

4) Steel rivets in double shear 
88,000 psi (607 MPa) 

c) The resistance to crushing of mild steel shall 
be taken as 95,000 psi (655 MPa) unless 
otherwise known. 

d) S = TS/FS. See definitions of nomenclature 
in S2.10.6. 



S2.10.2 RIVETS 

When the diameter of the rivet holes in the 
longitudinal joints of a boiler is not known, 
the diameter of rivets, after driving, may be 
ascertained from the Table S2.10.2. 



TABLE S2.1 0.2 

Sizes for Rivets Based on 
Plate Thickness 


Thickness of 
Place, inches 

(mm) 


Diameter of 
Rivet after Driving, 
inches (mm) 


1/4 (6) 


11/16(17) 


9/32 (7) 


11/16(17) 


5/1 6 (8) 


3/4(19) 


11/32(9) 


3/4(19) 


3/8 (1 0) 


13/16(21) 


13/32 (10) 


13/16(21) 


7/16(11) 


1 5/1 6 (24) 


15/32 (12) 


1 5/1 6 (24) 


1/2 (13) 


15/16(24) 


9/16(14) 


1-1/16(27) 


5/8 (1 6) 


1-1/16(27) 





S2.10.3 CYLINDRICAL COMPONENTS 

The MAWP of cylindrical components under 
internal pressure shall be determined by the 
strength of weakest course computed from the 
minimum thickness of the plate, the tensile 



1 33 



NATIONAL BOARD INSPECTION CODE • PART 2 — INSPECTION 



TABLE S2. 10.3.1 

Maximum Allowable Working Pressure for Cylindrical 

Components (Barrel) 

For Single Riveted Lap Joint 




0J 

\ 51 

JZ 

IS; 

c 
u 

is 
s 

3 

E 
'c 

5 


jfjif — ; 

US " f 


TT 


Q 


rj j 


S 


~,L| 


~\ 


■| 


5 


?! 


; 


™ 


?! s 


1 

■L J 9 


i 


fc 


K 


g 


5 


s 


£' 


0: : 


: 


- 1 : * 


-- 


^ 


3 


- 


■ffi 


3 -■ 


■if 


• ] 


s 


s 






- 


■- 1 


S 


p 


:; 


s 


1 


! 


2' 


o5- 


s 


1j 


;£] ^ 




? 


? 


S 


5 


rn j ^ rn j 


|j 


2 


r 


L 




isi ^ ; 




I 


2 




s 


5; 


b| 


~1 






s 1 


? ■'■—■ 


- 


~ 





s[?1k|s 


2 


2 




;L ; 


Sj; mI : '? 


Hi ^ 


*l "i 




" I 


z 


t\ 


2 


s 




S!§!l sis 










^1 - : 










s si 








O 


sj 








'i 


^C ! 






S 


s 


i 


£ S 1 R 


s 


2 


s 


E : 


2 




^ 




Si 


S|s| 


2 £ 


; s 


g9 3^ 






^ M 


1 


K 


H 


£ 


^ 





Oi 


5 


CO 


f; j k: 


* 


g 


T 


° 




5 


BS 


g 


f, 




3 


N! f 


^ £ 


|||| O 






S 1 


">! 




"^ 




" j <N 




s! fe 


■■ 




■ is 


^ 


S 


* 


5 
















- 


2 


= 




- : 


3 = 


a 




£ | 




5 


2 


§ 


1 


£ 


: 


£ 


s 




g 




S 


?s 


» 


C ■ 


^ 


s 


§L 


; 


E 


2 


1 6 


jjjS r; 


j 


I 


"1 " 


s 


1 




■-- 


9; 


c 


3'. 


" 


^ 


K 


2 











- 




S 




! &:| " 




si s 


a 




s 


^ 


i 
sL 






=5 


r-i 


1 


gig 




■'■■f': 


1 


s 




s 


•H 


5 








- 


S 


R 


3 8 


s s 


5 


crl 


i- 


HH ^ 


^ 


c 


~~1 


g 


'■'■■ 


?, 


S 


3 


0- 


■2. 


(I: 


.L 


2 


8'1 sbS 


s 


-. 


= 


.1; 


s 


„ 


„. 


^ 


"" "^ 


jL 


5 : - 


cr> 


S 


H ?, 


'■CTi. 


! 


E 


s 


? 




« 






.- 









e 






















ffi 


a 


|||| £ 


- 


- 


S j o, 




^'! 


~' 


s 


3 1 3 | l 


§ 


2 


K 


s 


ij 


? ' ^' 


"^■! ™ 


^-' 


r: 


z 


? 


2 


£ 


^ 


_ 




?! a 




Si '"" 


1 




J3 1- 


S 


o> 


o 


t, 


1 f r\ r 


1 


s 


5 


. ; -p 


■* 


s 


5 


IS ! ^ ! ff, 


g 


r 


° 




£ 


£ 


^7^ 


LO 


a 


5 1 s 


1 
'-■I 




P'i ? 




2 


5 


2 


a' s 


!!1 


2 


* 






a 


ilSL 


t » 
= 1 - 


t 




b 


3 


£ 


s 


? 




1 


?m ^ 


1 


7 


s s 


£ 












sis 


I 


2 


2 


3 U 


s 


1? 


5 


s! 


5 


S : S 




5 


S 


£ 


CO 


>c 


"* L 


s 


5 


I 


5 


r' 


5 


S2 


K 


2 


0; 




s 




s 


!£] = 


_E, 


£ 


9 








~ 


f| ? 


3! g 


§P§| -"■ 


c 


s 


r ■ r„ 














S 




s s 


-; 






2j £ 


1 


"" 




S 


sis 








?: 


Kl -T 


3 


r^. 


s 


5 


£ 
™ 




'■&■ 


O 


~s L 






- 




^ 




S 


s 


s| a 






1 1 


S 


! r 


pi r 


- 


s 


~ 


1 








Js 


^ 


£ 


^ 


s 


; . 







3 


8 


si t 


S 




SI s 


g 


=L 




R 




y§l '"5 


m 

TT 


" 


; 


CTj 




n 




o 


r| 5 


5 


K 


5- 


3 


"sill 


S 


g 




sli 


01 


S j 3 


g 


1 


r] r 


R^H -" 


R 


O 


i 




£ 


f; 


:<** 






5] = 




2 


TT 


c- 


3 


b 


s 






5 






r . 


s 


« 






" 


sU.s. 


iHi ~'' 


- : : 


(N 


S 














S 


?i : * 


| 


t 


O 


s 






■ vD. 





c 








§ 






s 




p; 


s sg ; 


jH 




3 


5 


c : 


S 


3 




? 


■^ 


S 


x;. 




= 


O 


~Sk'\ -■ 


s| § 




,1 g 





s 


s| S 




- 


CO 


s 


O 


■' tr 


H : 


s 




s 




s 


3 


■■*T 






s 


g 


- 










*'i s 


J. s 


1 1 




r|p[- 












■ 5' 


pH] !"■! 




O I"-. 


* 




T 


■ "T 








= 


* 


d 


■ CD 


J^ 


.1. 












S 




= 




C 


1 "^ 


n - 


.# 


S R 


3 


s 




3 






1 


^ 
- 




3 


c 










§ 




p; 




J'S 


T 


r 




s 


~ j fc 


W\ - 




R| X 












s 


= 


- 


5 


c-. 


~ 


& s a 


! 1 
S. 1 ^ 


R 




§ g 


1 


E 


g 






S 


Sy 


8 s 


5 






§ 




o 




- 


- 


s 


3 




? 







sLu 


L r lEl 


r; 


si a 




s s 


» 


; '!o : 


s 


s 


;? 


-J 


HH 




8 


5 




- 


s 


1 2 


I 2 


g 


a 






S 


j g 




skU 


J O 


sis 




LjsLL 








K 


" 


' 


a - 


I 


f" \"' 






L 


r~ ~ 


a 





h 


18 


j S 








'I SJ 1 S 


3 


1 L ~' I: ^ 


^Lj 




1 K 






fl s 


|K 


L 




E 








3 


|e 






jltL 




"7[ 1 LI 




in 




1 

v; 






^^^^i^^^^ - : 



01 £- 
E ^5 



0J 

c 
o 
a. 
S 
„ o 

§^ 

S-o CO 
&b >. >- 

* 0.2 
<« «.y 

™ g LLJ 

J u c 
1- x "o 



II II 



1 34 



NATIONAL BOARD INSPECTION CODE • PART 2 — INSPECTION 



TABLE S2. 10.3.2 

Maximum Allowable Working Pressure for Cylindrical 

Components (Barrel) 

For Double Riveted Lap Joint 



I 


4- 


h p 1 1 


4 
4 
4- 


4- -4 > A 







1 $ 




:C 




,uv 


shl*; 


§ 


,r 1 ,^ 


S S 


- 


r-i } r-j 


s S 


sj;|:l | 




2 


22 


H° 


u,UUI, 


d 


ei 


- 


^T '5 


s 


sj? 


lis 


" 


S 


2ji t~, 


r: 


£ 


1 


| 


sl S 


o 




2 


II2 


g 


! 


S |g 




- 


5 




1 :? 


"* ■*" ! * 


=5 i 


?|s 




■X 


S 


F; 


3 


f: 


?, 


sl s 


s ? 


s 


2:2 


^1 - 






s 


s 


s 


^ 


2 




H ? 


? 


■ ' 


£j J 


st ?. 


S 


* 


t, 


^ „ 


S 


■\£; 




" * g; 








2 






2 


^r 


- 


- 




B ? 




3 




^ 




Tip 


sly 




5 j 3 1 £ 


§ 


1 2 




R: S S 


-_ 


s 


S! 


0^ i L ^ 


5 1 




fas 


:'.■.'■■! t- ■■■■:■■■.■! |//:: 
.n. ; n i : :0-'| cc ; .m: 


; 


R 


j 


S : ^t 


sUU 


i -i « [•••£ 


3 


£j 5 


S j S ; .t 


i?iS 


s IS 


a 


! 


¥j j 


CTl 


S 


1 ' "• 


I.::'- 


2 ,2 


3 


= 


co ( .^r 


5 1 |s |l| a 


Si | ^ .-^ 


S 


2 2 5 




■5 '^ 


^ 


;£'' 


<r 1 ! r, 1 a- ■ # 


31 




6 co i-^r. 


~ ! iS : 


si s 


1 a | s 


3 IS 1 3 1 S 1 S, 


5 |[| 


s 


to 1 m t-'iC 


R t 


s 


' :K 


£ 


: 



-r 


■r-j 1 d 


^ s 


?~ 




•rr l.?r. 


O 


1 


si s 


7. 


l]4 Sis 


eci h> 


■ <£ i ^ 


e ste 


8 


?]7jr 


gj 2 


s 


. : .'■*' 


5 


U? 


■q- 


: : 


S 


s 


O 


2 




"■'"*■ 


cri 


- 


CO 


2 


s 


S i ~ 1 £ 


S Si S 


■■ ^j. ^ 


o ^ * j » | i^ r^ | ■& 


T 


: 2 


L2 


2|2 


2:2 


•5 


2 


a 








:;'.? 


-Z> 

co 


S 


m 


s 


o 


! 

00 ] f^ 




S R 




& 


1 


5 


C ; ^C CO i i"-.. 


ol ^ 





2 


- 


- -i 


: fflv1 ^C 


- 


^ 


s 


s 


- 


-T 


^ 


£ 


E 


» 


= 5 




CJ 


«R 


= 


s 


| 




sl g sl - 


3 'I 8 


S 


? ^ 


™j ; 




3 a 


2 




3 


2 




o 


^ 


CO 


4 r-i 


■' rn -i ■■-0 




1 


„ | -* 


s 




g 


s 


t 




i 


5 S 


61 


5 




s; 2 


a 







2 




" 


J H 


* 


*~ i ■■ £■' 


s 


bo 


Is 


2 




s 


Sj s 


3 


2 


i 


.■■?' 


\2 


2J2 : 2 


ir , 




2 


3 


2 


1 


■ ■.'*£' ! a> (---jin ia ! r-. 


p; 


fe 


t [■ ^ 




:- 


■vf j'i,o' 

Si S 




s|rr 




? 


« 


V 


tT 


^|J2 




2 r 


2 2 


- 




15 
1- 
E 

I 

= 

3 


; : c .. 


CTi !;'.K. 


S 


g 




- 


CO 


Si 8 


- - 


"s 


s 


2 2 2 2 


2 


2i 2 




5 


*r 122 
5 1 2 


en | : -co. 




^i 




rj ' ^i 


2i 5 


ct> j .'S0.:| I-. 


.' K. i o 


8 


t 


? 


-+ 
1- 


Ij ; : 


^ i.^- 


21:2 


2 5 


11° 


w 


| 


sU §|s 




"t 


■:Hi; 


•r [ ;M- 


3 


-" 


.-I" '-. 


LO ' i tr, 


2 


-^r 


1 


*\*\f. 


_ 




cci .r 


" g 






S 




*i\zh\% 




s 


s 


?U 


2 


- 

CO j I'S 


- 




l § h :-'■?! 3 


2 : - 


g $ 


s 


s 





x-j 


T^lolo 


sis 


? 




?, 


g 


1 l 1 

^! n L_o j eg 


S 


■'■'£■) O 




: 


_ LiJ = 


, 


2 


2 : g 


8 


s 




f, 


J 


s =]s 


[- 


3 - 




2 




5 


; ' r~'\ __ 


IS 


"| ^T 


s s 


8 


2 


1 


2 


3 


TT 





8 








;- 




«j M ['.f~l 


Sj 


Sn 


Il5 




S 


2 


2 


"i | ■ j 1 | 


s| s 




- 


OS- 


r. z 


s 


C2 




9 ^ 1:^ 


£i 






^ 


= 




3 


E 




Si K 


-J« -i - 


itatsftufls 


! 


1 


g 


I 




§ j,g 




3 


1 
1 


js d |.. cc 


j 


■Jn 


3 




1 








f*| ^ 




sis 






s 






in *fr 

9 °~' 


F; 


s 


51 


& 




g 


£ 




s 


,It 


■? 






r; 




s 


j, 


S 


8 


=0 J , 






m K 






si 2! 


8 




Kl 3 


S 


£ 


■£j' — 


B\ 2 


1 


= 1 








d n 


1 


Sj ? 


f | s S; 




s 


■' 


Si 5, S| S 






I 2 


*? i-j 


s 


S 


" 




1 


«= 


':? 


S 




o m 


= [ * - 


2 


Si 5 


g 


■ crN S 


£ 


« 


3'^d 


. ; i 


2, 2 


S 




M ^ 


si S 


"~ 


2 [2 


^ 




? 


g 


S 5 


S ! 2 


2J ?;] o 


3 


S § 


o 


C cc 


i6 


CO 


' S 


tv ■ r. r. 


r| 








» ™ 


'■-i 


g 


g 








: 




ol •* 


= : 2 


! 


g| S 


eo 


s 


: S 


i 


gi S 5 




:J 2 




fc; S 




3f 


■ 3 
■■*.. 




0] (N ;-':0' 


S 


5 


si s 


r„ 


?| S 


0- | m i a> 1 " 1 =- j 1- 


8 


5 






■CO j CO | K- 


£ 


r; 2 


Q 






jl ir, i: os- 
9 ^- !;.3-'. 


5 


■■'.£ 


l£ . i£ 


5 


: 


PT; 1 ^_" ;- 1 o c : ^ 


S 


en 


S 


g 


: 1 


';«_>'] ^ i::* 


a 


? i 


.0 2 


Si 2 


'.'■'Q- (Ti 


lis.- 


= B 












1*1. 























































(- 


<Z 












O 


o; 




-D 


O 












,™ 



E 

-^ o 

§!£ 

o re ^^ 

12 -D t 

m >- >- 

± v * 



5 u c: 

1- IE '5 

11 1 

m II M 



1 35 



NATIONAL BOARD INSPECTION CODE • PART 2 



INSPECTION 



TABLE S2.1 0.3.3 

Maximum Allowable Working Pressure for Cylindrical 
Components (Barrel) 

For Triple Riveted Lap Joint 



4- 


j— p--«i 


1^ 

4- 

4 
1 4- 


4--<?- 4^4) 

-(f)- -c^ -cj>- 

■4-4- 4- 4 









S 


i7 ' : tj-! s 1 3 


is 


§ 


s 


■■ 0: 


S 


- 


»l'* 


r^i j ^: ^ ■>■ r^ : "|| Si f <>; 


_ 


t'" l-'^-J 




k 


s|p 


Si 5 | ^ 


SMI '^ 


? 


5; £ 


§|? 


s 


s 







1 


gj s 


gj g| || gj S| g| 2 


s 


1 


?|^£ 


S 


s 




r! r o 




Pllf ^ 




gj 1 


Is 


5 


r- m 


S'. 


S j 1- ' -i - 1 ' , ! :| 1 ?! 




1 


S 


•gj 2| 5 


5 


^urur ? r^h' 


|H| 2 


-.- 


? ! ' ? 


5 


1 


s 


-r ^ c ^ 




111! s 


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T 




s 


s 


2 


a 


1 


r,| 1 Is [vSi 


[:■:.( j ' ; j! . 




5 


tj 


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5 


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Li? 2) gM 2 


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Hii — 


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1 


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S 







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S [ sC 


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n ; i^ ! '$ \ 3 




a 


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s 


L 


mm c 


# 


™ 





V si 5 


Sills 




5 


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£ 


5 


■ -■)■ 


S 


■■'Si 


_ 1 






n ' !B ' 3 1 5 


? 


s 


•T- -t 


§ 


B 








3 


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£ j S i S | m 


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5 


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; 11 





S| 










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js|n 


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$11$ "r 


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m 


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5^i r^ 




5 




s 


fe 


C^ 


« 


£ 1 S 


S! 2 


■x 




K| Ef p 


m S 








Si 




HI "^ 


I 5 


co 


5 


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§ g 


:^: s 


S 




si 


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s|k 




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s 


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aj 

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j: 


h3M "i" 


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co 


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s 


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f 


g 




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s, 


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■ co 


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CO 


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§1 = 


d^i|si?i 


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li? 




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5 


g 




SJijS 


s|l. 






L 


_ 


o 


sU 


s s 


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00 i 0, 


p.f 0^ 


•- 


?: 




£ 


5 


S 




5 


5 1 E 1 E 


si I; K 


J, 


£ = 


■st 


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S|S) 


0' 0- 

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T 


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3 






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3 


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;, 2 


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3 


£ 




5 


s 


CT. 


sfd « 


_ 1 . . 


°' - 


t 






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co 


■ cV. 


S 


'■.'-,' o> 


■ iO-; =C- 


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Cji 


:-' ; pi ) co 


OV 


s 


C3-. 


S 


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p 


s 


E=! 33 U 


2| 2 S 


S s| 3 




m ~ 


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Si 


sD 


In 


§ 


■Xi 


. Lj J ^ 1 M t -r 


S 


& 


t 


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5 


I 




P 




g 




E 2 2 § 


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9 f 


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2 s £ 


? 


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K 


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^ ! m ■ 




3 = ' S B 


~ 


^iffi 


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W 




Silt — 


'■■Si'' 


^ 


t 


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[ 


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3 




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1 ' 

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co [ co.. 




fii ~- 


£ 


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[■..'■■■..■■ 


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; i 1 | 




^2 




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$: 


£ 


5 


" s s is 




£ 


[ 










(NJ CN 






b |S 




! i) = 


?! 




3 °- 




— 




~ 








5 


r. 




IS " J 




sis 


m 


8 


'- 


s 


£ ; £ 


sj? 


~ r p;| C2 


s 


^ 


so.- ■* 


- 


■s * 


5 




T] ?H gU s 


3 


£ 


« 


' '.£'■ 

Is 




i- 




s 


- 


£' 


'£. 


" 




i|s: 


p B 


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'.'^ 


= 


2 


28 


1 


^ 


J? 


31 '. cC'. 3D '.OS-I CC 


■■ S-. 


i? 




R 






§$B§i -c ; 


T 


(N 


' Hi'' 


(T-. 


■ "j 

»|l 


:■-.«;] ^ [ :-ja. 


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2 


■2' 


5 




= 1 


6 | "p. 


»| J; 




g 


»i.c3. a, 5 ^ 






R 


pi 






fifi ° 


J 


£ 


8 


1 


fcl 2 


If i 


^ ^~ 


^ 


2- 


£ 










lilt' 






F .i 











llll 


■ C-. 


c 




lis 


S 


4 a 


□ * 


* 


g 


?M§t*la 


Si 0- l : r : 


a 


a U ftU 




s 





CO K 


S S 




Mf^S .r. 


s 


c 


2|£Ji|s 


"*'■.' 


■ : 


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^: 


!- [■■■■^';' ^ |. : '.:'^ : i 5i 


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cc 1 ^ f: 


CC 


■'■.Kv K ■:'' i H- ; K 


= 


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1 36 



NATIONAL BOARD INSPECTION CODE * PART 2 



INSPECTION 



TABLE S2. 10.3.4 

Maximum Allowable Working Pressure for Cylindrical 

Components (Barrel) 

For Buttstrap Double Riveted Joint 



-F$i 


I 


<H 


^ p ^ 4T 


-CjHJjCj)- -<•> -<■)- -<■>■ -cj> | 


^g^^^:^ j 


<H 


-4- ^> ^>-( 


<!>■; 


. 




"5 


3i 


h 


IT! 




C/5 











u 


JL, 


_„ 


6 



X ^ 



— 


o 




c 


u 










c 


r3 




in 


u 


fN 


ir: 


■o 






CO 




















c 


VJ 


c 








ir> 


iai 




qj 


ni 


tc 


"'" 


c 










£ 


.Irl 
IE 


o 



II II 



1 37 



NATIONAL BOARD INSPECTION CODE • PART Z 



I NSPECTION 



TABLE S2.1 0.3.5 

Maximum Allowable Working Pressure for 

Cylindrical Components (Barrel) 

For Buttstrap Triple Riveted Joint 




^KJ K&<j> & <!> ^ ^>jj> ± & & ■&& x ' 



4t-p^>— 



--=§= 



j ^ 




tfS 


S 


3 




3-. 




s ■§ 


s 


^ 


j I a 


5 


3 


en 


::■ 


31 


■ -3t : 






s 


1 


?. 


5 


?: 


£ 


■ cV 
■K! 


00 




r , 


Is 


3 


rJ 


s 


g 


- 


CI 


« 


r|s |r|j 






s 


s 


5 




■ \ 

■t j. : ,Cr.* O ! fM co 




? 




» 






: :■: 






si S 




K 







II 





£ 






o 




o 


U 




o 






o 


r3 




LT; 


ij 


CO 


ui 


"Q 


_c 


C 


CO 










S-- 




c 


u 




S-. 


ft 


a* 






wi 


;/l 


u 


-i 


flj 


tt 



II II 



1 38 



NATIDNAL BOARD INSPECTION CODE • PART Z — INSPECTION 



TABLE S2. 10.3.6 

Maximum Allowable Working Pressure for 

Cylindrical Components (Barrel) 

For Buttstrap Quadruple Riveted Joint 



-$- 



^~ 



r^rrrrrz^rzL 



_<^r -jr -6- -<•)- -&- -& -<■>- 






^F 



s- 



^ ^ w^ 





3 

CO 


■.;i-rV CTi '■kT.':| kfi f'-'S-J ^ 


..-5-. 


S 


2 


O 


■.'.■■**'■■' w 






— j c 


? 


'7C' 


P 




. 

5 


| 




S 


O' 


s 


, 


■* 


liiJliJilii 


S 


1 


^ 


# 


;.4 1 ^ 


■$■ 


1 |uj2 


lis 


'-^ p^ 


oj | 


oj - 


m | r~i : S I ^i i -ii | m 


» 


r^] rX | "- ' S 


■ ."**■] — 


3 


? 


5 


- is! 5 


r. 




s 


s 


| 2 .Si S 


Si g | Si S | R 


cc l:'(-.i' 


O 


- 




5 


.'■ : '«j':i -q- i'cft 

: .-:?t;] CD | : .'.Tf. 


vD 


f'A 




- 


o 


1 


j ! 
1 |'f 1 


£ 


t' =^ f 


s 


^t 


5- ° 


; 


CC 




s|s 


77 


s 


S 5 


i? 


s?! si s 


— 


■.c 


CO 


ffi' 


li 


3 


a i 2 1 S 


■ •— . ; kg |. f<j- j o 


§ 




g 


en 


■ -co 
■50 ■ 


CO 


;j:-,:j vo I'ln. 


1 


IS 


f 


- 




to 
D_ 

"53 


f: 


■'.■4i lt; i ■: ■— ■ 
.:;>■! vo j. ■•£■. 


CO 


'.-T — 


1 


1 


2 


«-, F:*tri i cC 






s 


5 


o 


s 




-,cc 


'■■■'■■■■ :-1 |:- ■'■': 
c^i |'.>~ij ^ ! -^i- 


1 

l.1 1 ■ 6>: 
1- /■>-! 


rU 


s s 1 


5 


:V^ : j Jg j ;.■'*■■ 


s s 


o f ' r-. 


S| 5 


5 ml ft 


si g 




K 


2 


o 


■'.;jT 


vf 


^l[.ih ?1-1 


1 S :s 


S 


s 




3 : 


" 


/;:'k£vj kC f Eft 


S '■ L^ 


.■: 


? 


j ;.' .. 


II 2 


R 


s 


fc 


s 


£ 


a 


5- ' r., I <r rv ! a 
Sj S| R, 3]w 


T 


s A 


fN 


b 


1 


^ 




: '/S; ] NJK 


s lJ.iill 


S 


^ 




"t 1 "■ 


3 




8 


o 


CO' 


^ 




.'■■.■*■.■! "^ !.^-' 


sis siS 


o 


J. 


s s 


o 


;'x:| 3 


7_ 


£ 


I di 


^ 


■ ?'■ 






■*.) g 


a 


3 


"■:"*. 


kC 


■\'S':.! <?■■ 


■'i'p-i'.l kc ['*. 


C*. 1 :' is'. 


sl 1 


s 


' ■£■ 


CO 


'■'■■■■J5'- r- 

■■■"!■! ; ~ 


=u 


Lf 


= 


1 




5 1 S ° | f ; 


« 


CN 


■ .'-' 


s 


-V = 


■'■'£:■'! S l ; '* t - 


77 


S 


I-. 1 -, 

~ ;. O 


■~53 


2 


1 


.— . 


kc 


■■■S/'l LTi 'i'l'tk 


1 




iflhliN 


?i = 


n 


co 


? 


S 


.'■ o 


s 






S 


■ ^i 


g 




a 


g 


CO 


- 


in 


■■■i'-t ^ ^ 


■* 


■ ■* 


5 


' : -r-' 


R S, S ! S 1 3 


■■ — . ] o 


a 


CO 


'■Jv'i 


§ 


?; 


-rf 


S ' - 1 ' 77 ' 77 


s 


? 


o 


s 


^ 


CO 


s 




CO 


'■-? 


j : ; 


"T 


■..o. 


3 


i 


^ 1 "^ ™ ^ '"5 i ^ 


■ 3 


en 


: 


i-O 


2 


s 


?, 


s 


~,j J *■! -I u 


5 


£ 


? 


2 


CO 


ft 


T 




kO 




C 1 ■ ? 


^ 


CO' 


■* 


-. 


slsNs'? 


■ 'y. 


5 


■. L ^. 


^O 


s 


co 


I S si Si 2 


S|'c 


s 


5- 


s 


s 


,- 




i 




H b 


[- 


^ 


5 


^ 


■ ,^- 


1 


■ ■:$' 


- - -- - - 


-- 


co 


s 


s 


o 


s s s! s 


si § 


; :? 


g 


s 


5 


!. 


s 


-' u* 




si o 


5 


o 


3c 


c^ 




R 


d- 


s!§ 


gj ffi 


5 


o 


; 


5 


s 


?,| U §! 77 


s|l 


S 






- 


s 


' -. J7„- 


2 flt 
•- 1 


i! c?> 

Ma '~o 


■£■ 


* 


T? 


■=f 


V.r^'l C-. | '.*;.! — 


■ ■ 'Si. 


- 


i;i 






sjss 


- " 


Si 1 


S| - 


g 


5 


1 


'■* " 






I S 




5| 


P 


■o 


§ 


■ 3 


i ! i 

-5t ; o>. cc- -co j ^~ 


S 


s 


§ 




1 


(N 


■. : .tn j ^O j 'CO- 1 — : 'r*-:' 


s 




s 


■ — 


CO 


I 


-!f 




s j s i s j g 






HI "i 


■ ^' : 


CO 


-i 


«T 






F, 


c : 


CM 


R 


O 


g 


f: : . ; - ] !"/.-;.] I ' 


o 


'■' S ; 


s 


3 


« 


,;| s 


3 g 




K j ? U ? 




1 £ 


.-.*$; 


"* 
-* 


5|l 


ii 3 


S 


S s 


■N i p 


s 


'cc' 




7 i 


3 


■T 


CD 


s 


-'• 


R 


Sl 3 


Si K 


K 


3 


c- 


7r m 




Hi o 


■ 3 


co j:;©) ^ 


r- 


3 




O 
O 




r., 


o 




-uU 


^ 


r^ 


- 








: r-.- '■ kc 


. 'ei\ co 










i § 


* ^ 


1 


3 


S 




9 


S' 


'■M- 




s 


3 73 2 fe 


lis £ 


s 


£ 


^ h'.jS i ;£ 


;,2l! 




,■1 


5' 




£ 


01 


cr- 


s 


l: 


5 


ffl s 


S| ^ 


s 


T^ 1 2 


=u 








sis Is 


- 




? 


§ 




R Sift 






1 col - 

31 T f.-.*f.' 


T 


. '.co 


s 


: -"i 


s 


CO 


Cr, |: :;l£r : 


; 


2 


S! 


r 1 


?b 


s e 


R) S| 3J S 


Tl.j? 


77 


5 




s 


77 =| si S 




3 "* 


5? 


Cf. 


- 




3 


^ i ^ j s \ % 


<N 


r-l 


- 


= S 


5 3 




3 -.& | S 


? 


5 






s s 


S §] c. 


s 




9 ■ rr 


is 


s 


o : ch. 






s 


OJ 


" 


B 


■J-'i cp- 


sU 


- 


s|s 




? 


S 








mi 




» ^ 


: AE 


£ 


Sis 8 




o o 


^1 


s 


s| " 


oj g 


r 

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3 


5 


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? 


? 


o 


■'■ vO ; 


R 






§ 




M 0~> 


O 


p) 


s 


-+ 


;£ 


fN 


?i 


rN 


7^ 


o 


' ~ 


^ 


■^*3 ^ 


tnl rs 


5 


S 


:+; 


; 


CO 


"T 


S 


U 


els,^ 


ill 


3 


s 1 


B 


P 


c 


s 


^ 


^ 


s 


?: 




=; 


1 


& 


= 


f 


& 


-1 - 


g 


; 


? = 




g 


2;! s 


!•- ; T ; -' : 3- 


1 | 






B s 


- 


s 


r 


o^ 


g 


o 


?, 


S 


2 


IV. ' 


■: 




SI ? 


2 




=[sjs 


s 


1 1 = 


= o 


2 




sLL 


5 


s 


SSI ™ 


s 


s 


% 


^0 


5 


CO :'K 

— ! : 0. 


i\s 


til u 


■ ■■£; 


2 


- I 


S 


- 


^ 1 5 = 1 z j z i £ 


■p ! O 


.- 




.. j^ — j, ^.... 
« » i - 




s: 


9 

en 





































































0J 


■ S 


J- 


re 


n5 










o 


0J 




T) 


o 






C 


kj 



II 

DC 



Q- 
E 

— o 

§^ 

« 4; ^*- 

-_, -o ^r 

■£= £ 

W) >. >- 

S u ^ 
^ »> .a 



II I 

I/) II " 

I— *- LU 



1 39 



NATIONAL BOARD INSPECTION CODE • PART Z — INSPECTION 



S2.10.4 STAYED SURFACES 

The maximum allowable working pressure for 
stayed flat plates and those parts which, by 
these rules, require staying as flat plates with 
stays or staybolts of uniform diameter sym- 
metrically spaced, shall be calculated using 
the following formula or Tables S2.10.4 and 
S2.10.4.1: 



P = 



T 2 x S x C 



See definitions of nomenclature in S2.1 0.6 



S2.1 0.4.1 STAYBOLTS 

Table S2.1 0.4.1 may be used to determine 
the MAWP for corroded staybolts. The table is 
based on a stress value of 1 1 ,300 psi (78 MPa) 
for staybolts that was the value used in the 
ASME Section 1, 1971 Edition. The table iden- 
tifies a calculated MAWP based on measuring 
the staybolt spacing on the crownsheet and the 
minimum diameter of the corroded staybolt. 
See Table S2. 10.4.1 



S2.10.5 CONSTRUCTION CODE 

To address the many pressure-related compo- 
nents and features of construction encountered 
in firetube boilers, a reprint of the 1971 Edition 
of Section I of ASME Boiler Code, Part PFT is 
provided for information only. This section 
may be used for actual repairs/alterations and 
inspection/evaluation of boilers. 



S2.10.6 NOMENCLATURE 

The nomenclature for the terms used in the 
above equations is: 

p = maximum pitch measured between straight 
lines passing through the centers of the 
staybolts in the different rows, which lines 
may be horizontal, vertical, or inclined, 
inches or mm 



R = inside radius of the weakest course of shell 
or drum, in inches or mm 

TS = ultimate tensile strength of shell plates, 
psi (MPa) 

t= minimum thickness of shell plate in the 
weakest course, inches or mm 

P = calculated MAWP psi (MPa) 

S = maximum allowable stress value, psi 
(MPa) 

C=2.1 for welded stays or stays screwed 
through plates not over 7/16 in. (1 1 mm) 
in thickness with ends riveted over 

C=2.2 for welded stays or stays screwed 
through plates over 7/16 in. (11 mm) in 
thickness with ends riveted over 

C =2.5 for stays screwed through plates and fit- 
ted with single nuts outside of plate, or with 
inside and outside nuts, omitting washers 

C =2.8 for stays with heads not less than 1 .3 
times the diameter of the stays screwed 
through plates, or made a taper fit and hav- 
ing the heads formed on the stays before 
installing them and not riveted over, said 
heads being made to have true bearing on 
the plate 

C = 3.2 for stays fitted with inside and outside 
nuts and outside washers where the diam- 
eter of washers is not less than 0.4p and 
thickness not less than t 

Note: The ends of stays fitted with nuts shal I 
not be exposed to the direct radiant heat of 
the fire. 

E = the efficiency of the longitudinal riveted 
joint 

The following is a table of efficiencies (E), 
which are the average for the different types 
of riveted joints. 



Type of Riveting 


Lap 


Butt 


Single 


58 




Double 


74 


82 


Triple 


78 


88 


Quadruple 




94 



1 4D 



NATIONAL BOARD INSPECTION CODE • PART 2 



INSPECTION 



TABLE S2.1 0.4 

Maximum Allowable Working Pressure for Stayed Surfaces per ASME Section 1, PG 46.1 



Thickness 
of Stayed 
Surface 






Staybolt Spacing (Maximum Pitch 










! 




Wm^K^mma^^^mimMmmB^m^^m^B^^m^m^mmmmm^mM 


HI 

BBS- 


84 ! 65 | 61 




52 j 49 1 46 | 44 42 , 


40 




36 ! 


35 J 




32 30 : 29 


94 j 72 I 68 


64 j 61 


57 i 54 | 51 j 49 i 46 j 


44 




: 40 I 






35 | 34 i 32 




80 1 75 ! 


71 67 


63 j 60 57 54 


51 


49 


_ 46 i 


44 ] 


42 ] 


40 j 


srprps 


1 : j 

111 1 88 j 82 


"8 ! 78 


69 66 6j 59 56 


53 


51 j 


44 


46 


44 


42 ; 41 


124 96 


90 


85 i 80 


76 72 68 65 | 61 j 


58 


56 


53 


51 ! 


48 


46 


44 


43 


135 i 104 1 98 




8 1 "8 ~4 "0 6 


64 


61 : 




55 i 


53 


50 1 48 46 


146 ! 113 ■ 106 


ioo ML' , 


89 j 85 80 | 76 72 \ 


69 


66 


63 


60 


57 


55 | 52 50 


HHHHH ma . ! . . : 
j 158 J 122 ■ 115 


108 7 102 


97 1 92 j 87 { 82 | 78 : 


75 


71 


68 






59 57 ! 54 


J | 171 | 132 124 


117 j 110 


104 j 99 94 


89 j 85 


80 






70 


67 


SiTLlj* 


? I8S | 142 1 111 


126 i 119 


112 j 106 \ 101 96 ' 91 




82 : 79 73 ; 72 j 69 1 66 j 63 


Bit; 


197 j 152 | 143 


135 j 127 


120 114 


108 1 103 97 


93 


88 


84 


81 


.ZL - 


74 


71 ] 68 


211 1 163 i 153 


111 I h 


129 12. ' 118 11(1 104 


99 


93 


40 


86 


82 


79 


; 76/5: 72 


f§JB| 


225 | 174 ! 164 


154 | 146 


138 ! 130 , 123 j 117 ! 111 


106 


101 


96 


92 


88 


84 


81 | 77 


240 I 185 ] 174 


1 64 j 1 55 


147 139 132 ! 125 j 119 


113 


108 




98 


94 


90 l 86 j 82 


^11111111 


255 | 197 j 185 


175 1 165 


156 148 ; 140 I 133 126 


120 




109 


104 


100 


95 91 88 




270 -209 1:97: 


1 85 i 1 75 


165 157 ; 148 141 1 111 






116 


111 


106 


101 : 1 97 ; 7393:7 


BBS 


287 | 222 209 


197 ' 185 


1 
175 j 166 


157 | 149 j 142 


135 


129 




117 


112 


1 07 1 03 


99 

1 04 


3(13 ; 235 i 221 


208 f 196 


185 1 176 1 166 ! 158 I 150 


143 


136 


130 


124 | 119 j 114 ! 109 


1 32 ° 


248 


233 


220 


207 


1 ! 1-9 


151 


144 


137 


131 


125 


120 | 115 


110 


IHBIII " i '"- . ui> 




219 :; 


20 T ! I96 | 1K5 17( t 167 


159: 


/7l52/7 : 


7 MS 


138 


1 12 


127 | 121 j 116 


156 | 275 j 259 


244 j 230 


218 ! 206 j 195 ] 185 176 


168 


160 


153 


146 J 139 


133 j 128 | 122 


"S "4 ' I'll] i i~i 


257 1 242 


229 217 206 : 195 : 185 


177 


i 168 


160 


153 


3 147:7 


140 I 134 : 129 


m 393 i 304 j 286 


270 j 255 


' 241 


228 j 2,6 | 205 | ,95 


185 


177 


169 


161 


154 


147 | 141 135 


lP*lllll 


413 : 320 1 300: 


283 ! 267 




239 '. 227 j 215 | 204 








169 


162 


155 ; 148 


142 
149 


sS»Bfev 


432 135 j 315 


297 


280 


265 


251 | 237 j 225 | 214 


204 


194 


185 


177 


169 


1 62 . 1 35 


HE 474 | 367 • l r 


325 


307:7 


"Hi 175 21-1 24" 1 2 13 


224 


» 21 3 


: 203 


1 91 


186 


178 7 1 170 ; 1637 


hH i 

W«i 496 384 361 


340 321 


304 


281 7 272 | 259 


246 


234 


| 223 


213 


203 


194 


186 178 | 171 


IIP 


I 518 | 402 I 378 


356 116 


317 


100 1 31.5 370 . 35- 


245: 




222 


2 12 


203 


194 186 ! 1711 


lllliPl 


j 541 ' 41 9 : 394 


371 | 350 


331 


1 
314 | 297 282 | 268 




\ 243 


232 


222 


212 


203 


1 94 ! 1 86 


itlllfe 


1 565 1 437 | 411 






327 I 310: | 294 : 280 


266 


j 254 


242 




221 


212 '' 203 194 




I 588 456 | 428 


j 
404 j 381 


L 360 


341 | 323 j 307 j 292 


278 


264 




241 


230 


220 | 211 ! 202 


TS = Tensile Strength (55,000) 
t = Thickness of Stayed Surface 
S = 13,800 

P = MAWP 




P = t 2 x SC/p 2 










c = 

c = 2.: 


1 2.1 if 7/1 6 in. or less 

! if more than 7/16 in. 

p = Maximum Pitch 



1 41 



NATIONAL BOARD INSPECTION CODE • PART 2 — INSPECTION 



TABLE S2. 10.4.1 

Maximum Allowable Working Pressure Based on the Load Carrying Capacity of a 

Single Corroded Staybolt 





Ipsi c 


o 


en 


z 


1 


I 

i 2 


s 


1 

1 m 


j 


' 


S 


1 :" 


| K 


s 


sU 


s 


■'■ ; 'k 


R 


h 


2 


5 


P 


s 


rrcr 


P 


HI '" 


i 5 


5 


1 


3 


2 


s 


§ 


I s 


a 


■+ 


", 




i " 
t 


si ~ 


' s 


|s|s 


, 3 I S 


- 


3 


s 


■ ^ 


[» ™ 




St^SI " 


■.'■-?' 


o 


ii 


sl 9 1 


§ 


1 
j K 


S 


j ^jg 


|l|*U 




R 




5 


Jj 


S 


o 


-^ 


5 


- 


™ 


Snfcj - 


r - 


1 
^ It 


s 


II 


c 


tN 


s 




p; 


3 


s 


§ 


ilj.p 


ft 


ft 


- 


1 


i 


-3§h 


:;'& 




a s 


?N 




s 




£ 


3 S 


S 


;? 


3 


I 




5 ? 




CTi 


■. ' 'T- 


2 


- 


o 


s 


o 


. a'' 
■.■en 




P* ,: 


'■■■*? 


" 


s 


■+ 


<; 


£ 




^ 






= 


- 


: : 


£ 


S 


^ 


« s 


s 


- 


£ 


S 


fe 




c 


■o 




i.. : ■■ 




f£^3 -"' 


:.■ 


1 


|] 3 f ;| 


R 


K 


s 


g 


S 


?! s 


s 


'- 


3 


S 






s 






" 






= 


-z. 




m 


£.' 


5 


. ; fN 


3 


s 


S 


1 


~ 




1 


3? 


' ^ 




- 


s 


s 


j 


2 | S 5 


fe 


a 


o 




j 1:! 
: 1 


o 

■Q 


H § 


■■§' 


3 


s 


o 


I? 


S 


s 


5 




s| ft 


s 








- 


-) s 


B 


g 


i 


o 


: ■■ ■ 


3 




^ 


t/1 

"C 
OJ 

-a 






s 


~h 


- 






« 








« 


s 


s 






-L 


a 


5 


« 


^ 


5 


S 


1 


g 




u 

re 


H ;: " 


s 




,., 


- 


g 


£ 


£ 


3 












s 


a 




f . 






R 1 


■*'■! ° 


3 


5 

3 

E 
'c 
1 


>j 


r 


<& ['m'.l .- j V-- 




s 


5 


a 






- 


■ O 


o 




s 




s 


- 




- 




S 


1 


S3 


2 


" 


§ 


s 


5 ft 


?r 






s 


3 


B 


o 




■N 


..■^' 


3 


E 


- 


^ 


■ 


S 


2 


5 


s r 


•T ■ 


■J- 


g 


- 


2 


2 




5 


3 


2 


2 


8 § 


s s 


CO 


5 




■*f 


- 


s 


I' ' 


3 




s 


s 


1 


: 


5 


s 


? 


? 


a 


- 


2 


8 


5 £ 




5 




rC 


o 


fe 


s 


3 


s!u 


S 


S 


K 


-^t\ 


•3" 


'* 




: if]' 


~ 


3 


Si 5 


s 




s 


g 




to 


f: 




p 




s 


s 


CC 


S 


s 


K 


5 


?. 


iX 


.■T+' 


5 


- 




|f|| ~1"' 

Sail " n 


■ !?■'■ 


- 


- 


S o 


§ 


£ 




5 






3 


::^:j \£> 


:-3 


s 




s 


KD 


■t 


* 


i? 


5 


5 


9 S 


t. 




'^ 


- 


sis 

~i 


g 


s 






8 


8 


3 


,cr ;: 


!?. 


5 


3 


.; 


■*■ 


* 


?u 


§ 


S 




J, 


s 




Hi ^ 


= 


■t 


: !■■■'■.. 


f 


5 






- 


to 


S 


■ --1 . 


o 


5' 


TO 


? 


3 


$ 


Sift 


" 


s 






S 




iHS O : 


s? j 


s 


i 5 H 


-i 


5 


1 


*| 


3 


; 


- 


* 


^r 


* ■? 


a 


ft i 


s 


"1 " 




- 


=; 






_ 




g 


5 


fS 1 FT fe| 




s| 


j 


pj 


■T 


s 




5 S 


1 


I 


s. 




51 


sis 


Si 


■(> ! 


S 




S 




B ~i 


'•" ; 


1 1 


zo 


"1 1 




4 


3 


« 


5 


CO 


... 


s 


5 


s 


s 


ft 


s s 


s 






- 


o 


"o c 

>- re 

55 t/i 












1. . - 




^I 1 ) 

^^^^^^^M 


g 



xs 
< 



-a 
o 
(J 



tN 

6 



55 



1 42 



NATIONAL BDARD INSPECTION CODE • PART 2 



INSPECTION 



Note: The efficiency of a particular joint 
depends upon the strength of the plate 
and rivet, thickness of the plates and the 
diameter of the rivets. The 1971 Edition 
of Section I of the ASME Code, Appendix 
A-1 through A-7, provides a method for 
calculating a specific joint efficiency that 
may be used with the concurrence of the 
Jurisdiction. 

FS = Factor of safety 

FS = 4 For stayed surfaces 

FS = 6 For riveted lap joints 

FS = 5 For riveted buttstrap joints 

Note: A Jurisdiction may mandate a higher 
design margin or permit a lower design 
margin, but in no case may the factor of 
safety be less than 4. 



S2.10.7 LIMITATIONS 

a) The maximum allowable working pres- 
sure shall be the lesser of that calculated 
by S2.10 or the MAWP established by the 
original manufacturer. 

b) The shell or drum of a boiler in which a 
"lap seam crack" extending parallel to 
the longitudinal joint and located either 
between or adjacent to rivet holes, when 
discovered along a longitudinal riveted 
joint for either butt or lap joint shall be 
permanently discontinued for use under 
steam pressure, unless it is repaired with 
jurisdictional approval. 



S2.11 BOILER INSPECTION 

GUIDELINE 

a) The following form may be used as a guide- 
line for documentation and inspection of 
historical boilers. Jurisdictions may require 
additional inspections and documentation 
otherwise noted in this guide. The owner 
and Inspector should be aware and under- 
stand jurisdictional requirements where the 
historical boiler will be operated. 



jurisdiction Number. 



Owner 



Location 

Make 



Year 



Engine No. 



Heating Surface 

Design Pressure 

Current Operating Pressure 
Inspector 



Safety Valve(s) Setting 



Total Safety Valve Capacity 



b) As a minimum, the inspection shall include 
consideration of the following: 

1) Smoke Box 

a. Front Tubesheet 

1 . Check condition of front 
tubesheet and thickness 
around handhole openings. 

2. Check condition of threaded 
openings and plugs. 

3. Check condition of rivets 
between front tubesheet and 
barrel. 

b. Tubes 

1 . Are tubes beaded back to the 
tubesheet? 

2. Are there signs of leakage? 



1 43 



NATIONAL BOARD INSPECTION CODE • PART Z 



INSPECTION 



c. Check condition of smoke box shell 
(especially around lower surfaces). 

d. Check inside condition of barrel 
and outside diameter of tubes for 
corrosion and scale. 

e. Check back side of tubesheet (espe- 
cially area in contact with handhole 
gasket and area where tubesheet 
joins barrel). 

f. Check tubesheet supports (through 
stays, supports or strong backs). 

g. Check inside rivet heads on lap or 
buttstrap joints, if possible. 

h. Check front bolster (front axle) at- 
tachment points inside barrel. Note 
thinning of the lower smokebox 
section of the barrel is critical if 
the steering bolster attaches fully 
or partially to this thinned area. 

2) Barrel (shell) 

a. Check front bolster attachment 
points on the outside of the barrel, 
both within and without the present 
boundary. 

b. Check condition of tubesheet rivets 
on outside of barrel. 

c. Check condition of threaded open- 
ings and plugs in openings. 

d. Check radius rod attachment 
point. 

e. Check attachment points of studs, 
castings, brackets, accessories, 
etc. 

f. Check piping and nozzle openings 
on shell (feedwater nozzles, steam 
outlet, water column, etc.). 



g. Check handhole openings in bar- 
rel. 

h. Lap seam or buttstrap 

1 . Check for leakage around 
riveted seams and joint rivets. 

2. Confirm joint efficiency based 
on number of rows of rivets 
and type of joint. 

i . Identify and check any external con- 
tour that does not appear normal. 

j. Insulation or Insulation Jacket (lag- 
ging) 

1 . Does jacket cover any critical 
areas or make them difficult to 
observe? (Normally the jacket 
will need to be removed for 
inspection of the barrel.) 

2. Is barrel pitted or corroded 
under jacket? 

3) Wrapper Sheet 

a. Check handhole openings (material 
thickness, gasket area, etc.). 

b. Check for seepage around attach- 
ment points (wing sheets, axle sup- 
ports, etc.). 

c. Check condition of riveted seams 
joining wrapper to throat sheet and 
rear head. 

d. Check condition of riveted seams 
joining throat sheet to barrel. 

e. Check external shapes or contours 
that do not appear normal. 

f. Check for seepage around staybolt 
heads. 

g. Check condition of staybolt heads. 



1 44 



NATIONAL BOARD INSPECTION CODE • PART 2 — INSPECTION 



h. Check condition of threaded 
openings. (May need to remove 
nipples and plugs.) 

i. Check internal surfaces for cracks, 
pits, material thickness, and scale. 

j. Check staybolt thickness and condi- 
tion. 

k. Check for scale and mud buildup 
in waterlegs and wet bottoms. 

I. Check for buildup of dirt and grease 
between or behind attaching brack- 
ets such as wing sheets. 

m. For dry bottom boilers 

1 . Check riveted seams at bot- 
tom of waterlegs in ash pan 
area (ogee ring). 

2. Do you need to remove ash 
pans and grates to observe 
above seams? 

3. Check condition of grate sup- 
port brackets. 

n. For wet bottom boilers 

1 . Check ash pan area for pits 
and staybolt head condition. 

2. Check inside bottom of wrap- 
per and staybolt condition. 

3. Check condition of lap seam 
in wrapper. 

4. Check condition of ash pan 
drain tube if present. 

5. Check condition of drain plug 
and plug threads. 

6. Check condition of studs, es- 
pecially studs holding hitches 
to the bottom sheet. 

o. Check for condition of blowdown 
valve. Check for size and type. 



4) Steam Dome 

a. Check for condition of drain back 
holes in shell if possible. 

b. Check condition of main steam stop 

valve. 

c. Check condition of piping on the 
steam dome and the condition 
of the steam outlet piping on the 
steam dome. 

d. Check condition of the steam dome 
seams and seams between the 
steam dome and the boiler shell. 

1 . Is seepage present? 

2. Can interior seams be ob- 
served? 

e. Check the condition of pressure 
gage. 

1. Is there a siphon and what is 
its condition? 

2. Is the gage readable from the 
operator's position? 

3. Has the gage been calibrated 
or checked against another 
gage? 

4. If a shutoff valve is present, 
its handle shall indicate open 
position, 

5. Gage checked for correct 
range and pressure. 

f. Check for condition of safety 
valve. 

1 . Does the safety valve have its 
own inlet/outlet piping with 
no intervening block valves 
and no possibility of isolation? 

2. Check that the inlet pipe size 
is not smaller than the valve 
inlet size. 



1 45 



NATIONAL BOARD INSPECTION CODE • PART 2 



INSPECTION 



3 . Check that the outlet pipe size 
is not smaller than the valve 
outlet size. 

4. Is the safety valve a National 
Board capacity certified, ASME 
"V'VNational Board "VR" 
stamped valve of proper set 
pressure and capacity rating 
for the boiler heating surface? 

5. Does the safety valve have a 
try lever (hand lifting lever)? 

6. Is the safety valve sealed with 
factory seals at the top pres- 
sure adjustment cap and at 
the blowdown ring adjust- 
ment point? 

5) Water Column and Gage Glass 

a. Is the gage glass calibrated to the 
level of the crownsheet? 

b. Check condition of try cocks, gage 
glass stop valves, gage glass drain 
valve, and water column drain 
valve. 

c. Check condition of gage glass 
(cracks or scratches). 

d. Check the upper and lower gage 
glass packing for signs of leakage. 

6) Firebox 

a. Check for bulging between stay- 
bolts and warping of the boiler plate 
(What caused this?). 

b. Check riveted seams around the fire 
door. 

c. Check for sediment buildup over 
the fire door opening at the rear 
head. 

d. Check for sediment buildup over 
the peephole opening in the wrap- 
per sheet (where applicable). 



e. Check condition of fusible plug. 
(The plug must be removed for 
observation). 

1 . Is it stamped ASME standard? 

2. Check condition of top 
surface for scale and bottom 
surface for tin corrosion. (May 
need to brush it off.) 

3. Check for signs of leakage be- 
tween the tin center and brass 
casing. 

f. When the fusible plug is removed, 
check crownsheet thickness at that 
location and thread condition. Are 
weld repairs required? 

g. A fireside fusible plug must project 
a minimum of 3/4 in. (17.8 mm) 
into the waterside. 

h. Fireside fusible plug may not extend 
into fire area more than one 1 in. 

(25 mm) 

i. A gage glass calibration can only be 
done when the crownsheet and fus- 
ible plug and gage glass can be seen 
and measured. A recommended 
minimum water level may be de- 
termined as follows: With engine 
(boiler) sitting on level ground and 
water just observable at the bottom 
of the gage glass, the crownsheet 
should be covered by at least 2-1/2 
in. (64 mm) plus of water on a full- 
size boiler. 

j. Check staybolt condition, especial- 
ly near top surface of crownsheet. 

k. Check through stays, strong backs, 
knee braces, etc., on rear head. 

I. Check handhole openings, threaded 
openings and plugs in rear head. 



1 46 



NATIONAL BOARD INSPECTION CODE • PART Z 



INSPECTION 



m. Check condition of firebox tubesheet 
and check if tubes are beaded back 
to the tubesheet. 

n. Check condition of staybolt heads 
inside the firebox. 

o. Check condition or design of 
crownsheet. Is it flat-topped or able 
to trap water? Is it free of scale? 

7) External Plumbing (See S2.7.1) 

a. Is black pipe (as opposed to galva- 
nized pipe) used throughout? 

b. Check for use of schedule 80 black 
pipe required between boiler and 
first valve. 

c. Are fittings and valves of proper 
pressure rating for maximum allow- 
able working pressure? 

d. Are isolation valves present to shut 
off individual system lines (blower, 
injector, main steam, blowdown, 
etc.)? 

e. Are two separate feedwater systems 
present and operable? 

f. Check piping for freeze damage. 

g. Are piping support brackets present 
where needed? 

h. Fittings dates are to be stamped, 
stenciled, or recorded on boiler 
records (boiler log). 

i. Piping shall have a 20 year life, 
except for the main steam line, 
which shall be periodically evalu- 
ated as to remaining service life. 
As an alternative, all boiler piping 
may be ultrasonically examined for 
adequate thickness to determine 
the remaining service life. 



8) UltrasonicThickness Testing (every fifth 
year). 

9) Hydrostatic Pressure Test (minimum 
every three years or as required by the 
Jurisdiction). 

a. Hydrostatic pressure test should be 
between maximum calculated al- 
lowable working pressure and 1 .25 
times maximum allowable working 
pressure with metal temperature at 
60°F-120°F. 

b. A calibrated pressure gage shall be 
used when hydrostatically pressure 
testing a boiler. The boiler gage 
may be compared (calibrated) with 
the calibrated pressure gage at this 
time. 

c. All safety valves shall be removed 
during the hydrostatic testing of the 
boiler. 

1 0) Safety Valve Testing 

a. Safety valves should be removed 
from the boiler for testing and/or 
repair at intervals required by the 
Inspector or the Jurisdiction. 

b. Safety valves may be try lever 
checked for operability with the 
boiler under steam pressure of at 
least 75% of the set pressure of the 
safety valve. 

c. Safety valves may also be tested 
initially, periodically and after any 
repair or adjustment as noted in 
the External Operating Test listed 
below. 

11) External Operating Test (every third 
year) 

a. The safety valve should be tested by 
having the operator raise the boiler 



1 47 



NATIONAL BOARD INSPECTION CDDE • PART Z — INSPECTION 



S2.12 



pressure to the safety valve popping 
point and popping point pressure 
and blowdown observed to be 
within manufacturer's tolerances. 

b. Feedwater devices (two injectors, or 
one injector and one pump) tested 



for operability. 



c. Cage glass stop and drain valves and 
gage cocks checked in service. 

d. Blowdown valve(s) tested as op- 
erational and discharging to a safe 
location. 

e. Operation of the steam engine by 
the operator satisfactory, including 
a driving test. 

f. The external operating test to be re- 
corded in the boiler records (boiler 

log). 



INITIAL BOILER CERTIFICATION 
REPORT FORM 



Form C-1 may be used to document the initial 
inspection for historical boilers. (Form C-1 is 
located at the end of this supplement.) 



S2.13 GUIDELINES FOR HISTORICAL 

BOILER STORAGE 

The historical boiler guidelines published here- 
in list the general recommendations for storage 
of historical boilers. The exact procedures used 
by the owner/operator must be based on the 
conditions and facilities at the storage facility. 



1 ) The anticipated length of time the his- 
torical boiler will be stored; 

2) Whether storage will be indoors or 
outdoors; 

3) Anticipated weather conditions during 
the storage period; 

4) The availability of climate-controlled 
storage; 

5) Type of fuel used; and 

6) Equipment available at the storage 
site. 

b) Indoor storage can be categorized into 
two types: indoor with climate control and 
indoor without climate control. 

c) Outdoor storage can also be categorized 
into two types: outdoors during a warm 
time of year or in a geographic location 
where it can reasonably be expected to 
be above freezing during storage, and 
outdoors during a time period or in a geo- 
graphic location where it can be expected 
that freezing temperatures will occur during 
storage. 

d) Historical boilers may be stored using the 
"wet method" or the "dry method." 

e) Before any method of storage, the boiler 
must be thoroughly washed out with mud 
and scale removed from the mudring, 
crownsheet, bottom of the barrel, and the 
top of the firing door. 



S2.1 3.1 .1 WET STORAGE METHOD 



S2.13.1 STORAGE METHODS 

a) The methods for preparing a historical 
boiler for storage depend upon several fac- 
tors, including: 



a) When utilizing the "wet storage method," 
the boiler is completely filled with treated 
water to exclude air. 

Note: This method cannot be used if the 
historical boiler is exposed to freezing 
weather during storage. 



1 48 



NATIONAL BOARD INSPECTION CODE • PART Z — INSPECTION 



b) Chemicals may be added to the storage 
water to further inhibit corrosion. How- 
ever, depending on the chemical used, the 
treated water may have to be disposed of as 
a hazardous waste to prevent chemical con- 
tamination of the surrounding property. 

c) The procedure applies only to the sections 
of the boiler that contain water. The firebox 
interior, cylinders, piping, and auxiliary 
equipment of the historical boilers still 
require draining, preservation, and dry 
storage. 



S2.1 3.1 .2 DRY STORAGE METHOD 

a) When utilizing the "dry storage method" 
the boiler is completely emptied of water, 
dried out, and allowed to stand empty. 
Several variations of the "dry method" may 
be used. These include but are not limited 
to: 

1) Air tight storage with moisture absor- 
bent placed in trays in the boiler; 

2) Air tight storage with the boiler filled 
with inert gas to exclude oxygen; 

3) Open air storage with the mudring 
washout plugs or handholes removed 
to enable air circulation for evaporation 
of formed moisture. 

b) Each variation has positive and negative 
points that must be taken into account 
before use. If the boiler is filled with inert 
gas such as nitrogen, care must be taken 
because this method can result in asphyxi- 
ation of personnel if the gas escapes the 
boiler through a leaking valve, washout 
plug, or handhole and enters a pit, sump, 
or enclosed room. In addition, the boiler 
must be completely vented to remove gas, 
then tested and declared gas free before 
personnel may enter. 



c) Although the use of dry storage with several 
washout plugs or handholes removed for air 
circulation is the most common method, 
there are some potential drawbacks. The 
boiler interior may be subject to moisture 
forming from condensation created from 
humidity changes in the ambient air. Small 
animals may take up residence inside if 
screens are not used to cover handholes 
or washouts. 

d) Before storage, the boiler must be thorough- 
ly washed out with mud and scale removed 
from the mudring, crownsheet, bottom of 
the barrel, and top of the firing door. Any 
mud or loose scale left in the boiler will 
retain moisture leading to corrosion. After 
washing, water must be removed and the 
boiler dried before storage. A portable gas 
or electric heater placed in the firebox to 
aid evaporation and drying along with a 
vacuum used to siphon water out via the 
lower washout plugs or handholes is rec- 
ommended. 

Note: Use of the drying out procedure of 
building a small wood fire in the firebox is 
not recommended because of the danger 
of overheating the firebox sheets. 

e) The typical railroad dry storage method 
required blowdown of the boiler until 
empty while steam pressure registered on 
the gage and removal of the washout plugs 
or handholes while the shell plates were 
hot and there was no steam pressure. This 
allowed the heat remaining in the boiler 
plates to evaporate remaining water in the 
boiler. However, this method may result in 
staybolt damage from temperature change 
and requires extreme care, if used. 

f) Oil should not be applied to the interior 
surfaces of the boiler because it is difficult 
to remove. Further, the oil must be removed 
before steaming or it will form scale and 
contribute to foaming. 



1 49 



NATIONAL BDARD INSPECTION CODE ' PART 2 



INSPECTION 



S2.13.2 RECOMMENDED GENERAL 

PRESERVATION PROCEDURES 

a) When the historical boiler is under steam, 
inspect piping, fittings, and appliances for 
steam and water leaks that may introduce 
moisture into the lagging. Repair leaks as 
necessary and remove wet lagging insula- 
tion. 

b) Remove grates and ash pan bottom if dry 
bottom. Remove washout plugs and hand- 
hole plates. Mark handhole plates and 
washout plugs for proper relocation. 

c) Thoroughly wash the boiler and firebox and 
remove mud and scale from the mudring, 
crownsheet, bottom of the barrel, and top 
of the firing door. Any mud or loose scale 
left in the boiler will retain moisture leading 
to corrosion. 

d) To protect the boiler interior during stor- 
age, dry the boiler by using compressed 
air to blow out as much water as possible. 
A portable heater placed in the firebox to 
warm the boiler to 200°F (95°C) along with 
a vacuum used to siphon water out via the 
lower washout plugs or handholes can aid 
evaporation and drying of any moisture 
that collects in low or impossible-to-drain 
locations without harming the sheets. 

Caution: To prevent a build up of steam 
pressure during the drying process, an 
opening in the upper part of the boiler 
should be opened to enable the moisture 
to escape. In addition, the driving wheels 
should be blocked and the throttle and 
cylinder cocks should be opened to permit 
any steam that forms to escape. 

After drying, it will be necessary to either 
vent the boiler or to place containers of des- 
iccant inside the boiler through the dome 
cap to absorb any condensation that may 
occur during storage. Venting the boiler to 



allow air circulation is accomplished by 
leaving two or more of the lower washout 
plugs or handholes out and opening the 
vent valve on the top of the boiler. A vent 
line consisting of two 90° elbows and pipe 
nipples should be installed in the vent valve 
to locate the opening to the downward di- 
rection in order to keep rain or snow from 
entering the open valve. 

e) To prepare a historical boiler for storage, 
the following should be completed: 

1) If the historical boiler will be stored 
outdoors, inspect the boiler jacket and 
confirm it is tight with no gaps leading 
into the lagging or shell. Pay close at- 
tention to areas at shell openings such 
as for studs, safety valves, etc. Repair 
gaps or damaged jacket sections as nec- 
essary. Consideration should be given 
to covering the entire historical boiler 
and equipment with a tarp. Otherwise, 
jacket openings should be covered to 
prevent the entrance of rain or snow. 
Where necessary, apply a waterproof 
covering over the exposed or open 
sections. 

2) If the historical boiler will be stored 
outdoors, the smokestack should be 
sealed by applying a wood and sheet 
rubber cover held in place by clamps 
or a through bolt. 

3) if the historical boiler will be stored 
outdoors, the safety valves should either 
be covered or removed, with plugs or 
caps installed in the holes if the valves 
are removed. The governor and lubrica- 
tors should be covered. 

4) Clean tubes using tube brush or scraper. 
After cleaning use a long air nozzle or 
vacuum to remove any loose coal or 
ash. 



1 5D 



NATIONAL BOARD INSPECTION CODE • PART 2 



INSPECTION 



5) Empty and clean the smokebox and 
front tubesheet of all coal, ash, or burnt 
oil. This work is especially critical at 
the bottom section of the smokebox 
and front tubesheet rivet flange. The 
smokebox door should be sealed by 
applying a gasket or sealant and any 
other air openings in the smokebox 
sealed. The exhaust nozzle should be 
sealed by applying a wood and sheet 
rubber cover held in place by clamps. 

6) Thoroughly clean the firebox sheets of 
coal, ash, and clinker. 

7) The potential for corrosion of the 
smokebox interior, front tubesheet, and 
fireside of the firebox sheets can be 
further minimized by applying coating 
of light oil, outdoor paint, or primer. 
Inspection of the smokebox, front 
tubesheet, and firebox sheet must be 
accomplished before painting since it 
will cover up many types of defects. The 
coating will burn off quickly when the 
historical boiler is returned to service. 

8) Empty and clean the grates and ash 
pan of coal and ash completely. This 
work is especially critical at the sec- 
tions between the grate bearers, rivets, 
and firebox sheets; and from the grate 
segment air openings. 

9) Appliances and piping that might con- 
tain water or condensation should be 
drained and blown dry using dry com- 
pressed air. Remove injectors and store 
in a warm place. Refer to S2.1 3.3, Use 
of Compressed Air to Drain Historical 
Boiler Components, for details. 

10) The cylinder castings, valve cavities, 
and steam lines must be drained of 
moisture and blown dry. Typical meth- 
ods include: 

a. Pressurize the boiler with com- 
pressed air. Using the throttle to 



regulate the airflow, allow the air 
to blow through the dry pipe and 
discharge into the cylinders. The 
cylinder cocks must be open. 

Note: This may have to be per- 
formed several times to discharge 
the moisture from the cylinders and 
steam pipes. 

Refer to the S2.13.3, Use of Com- 
pressed Air to Drain Historical 
Boiler Components, for additional 
information. 

1 1) Drain and wash tender water spaces. 
The tank should be inspected afterward 
and any remaining water removed by 
syphon or vacuum. When dry, spray 
the water space with outdoor paint or 
a commercial rust preventative. Oil 
should not be used. Drain and dry the 
tender tank hoses and clean screens. 

1 2) On coal or wood burners, remove coal 
or wood. Spray any exposed surfaces 
of the tender fuel space with outdoor 
paint or a commercial rust preventative. 
If the historical boiler is to be stored 
outdoors for long term, cover the coal 
space with a tarp or a roof. 

13) After cleaning thoroughly, coat con- 
necting rods, cross heads, valve gear, 
guides, piston rods, and exposed feed- 
water pump components with water- 
resistant grease or a rust preventative. 
If the historical boiler is to be stored 
outdoors for long term, grease should 
be applied to junction of rod and pin 
in valve gear and rods to prevent water 
entering. 

14) If the historical boiler is moved after 
this is applied, it will be necessary to 
reapply the coating to piston rods and 
guides. 



1 51 



NATIONAL BOARD INSPECTION CODE • PART 2 — INSPECTION 



Note: Heavy oil or unrefined oil such 
as any of the Bunker types (Bunker 6, 
etc.) should not be used for preservation 
of any components because the sulfur 
contained in it can accelerate corro- 
sion. Standard motor oil or journal oil 
will not stick to and preserve wetted 
surfaces. Surfaces to be so coated must 
be dry. If moisture is a problem, steam 
cylinder oil should be applied. 

15) All openings in the boiler should be 
covered to insure water and contami- 
nants can not enter the boiler. Hand- 
holes and plugs left out for air circula- 
tion should be covered with screen to 
prevent small animals from entering 
and taking up residency in the boiler. 
Secure all openings and covers on the 
top of the water tender to prevent ac- 
cidental opening with the potential for 
water and contaminants to enter. 

16) If the historical boiler is to be stored 
outdoors with questionable or no 
security, remove and store all cab 
gages, water glasses, lubricators, brass 
handles, whistle, headlight, tools, spare 
parts, and any other items that thieves 
or vandals might attack. 

1 7) Inspect stored historical boiler regularly 
for signs of rust, corrosion, damage, 
deterioration, vandalism, or animal 
invasion and immediately take any 
corrective measures necessary. 



b) The air compressor must be equipped 
with a suitable filter to enable it to supply 
oil-free air because the introduction of air 
that contains oil into the water/steam parts 
of the boiler will promote the formation of 
scale and water foaming when the historical 
boiler is returned to service. 

c) The air compressor must be a large enough 
size to provide the volume and pressure of 
air required. 

d) If the boiler is pressurized with compressed 
air, the air pressure must be raised slowly 
to prevent distorting or overstressing the 
firebox sheets or staybolts because the 
normal expansion of the boiler that occurs 
under steam pressure is not present when 
air pressure is used. 

e) When pressurizing the boiler with air, the 
pressure should never exceeded 3/4 of the 
maximum allowable working pressure. Air 
shall never be used for pressure testing the 
boiler. 

f) Components are drained by pressurizing 
the boiler to 1/2 to 3/4 of the maximum al- 
lowable working pressure with compressed 
air, then operating each component indi- 
vidually until the exhaust from it contains 
no moisture. 

g) When necessary, specific pipe lines can be 
drained by breaking the line at each end, 
attaching the air line to it directly then 
blowing the line out. 



S2.13.3 USE OF COMPRESSED AIR TO 
DRAIN HISTORICAL BOILER 

COMPONENTS 

a) The process of using air pressure to drain 
and empty auxiliary components such as 
the cylinders and piping completely of 
water offers several advantages over other 
methods. 



S2.13.4 RETURN TO SERVICE 

a) When returning a historical boiler to ser- 
vice, the boiler, firebox, and tender tank 
shall be ventilated to remove potentially 
hazardous atmosphere from the firebox 
interior before personnel enter it. In addi- 
tion, the atmosphere in the firebox shall be 
verified to be safe for human occupancy 



1 52 



NATIONAL BOARD INSPECTION CODE • PART 2 — INSPECTION 



before personnel enter it. For the boiler 
this can be accomplished by removing the 
washout plugs or handholes and placing a 
fan or air blower on top of a steam dome 
opening to force air into the boiler. For the 
firebox this can be accomplished by open- 
ing the smokebox door and firebox door 
and placing a fan or air blower at either 
location to force air through. Failure to do 
this could result in asphyxiation of the first 
personnel to enter the boiler or firebox. 

b) Perform a complete boiler flush to remove 
scale that has flaked off during storage as 
a result of the expansion and contraction 
of the metal due to temperature changes 

c) Clean handhole plate gasket surfaces (both 
boiler and handhole plate). These surfaces 
must be flat and free of scale, rust and dirt 
in order to seal. 

d) Inspect feedwater inlet connection to boiler. 
There should be a tee at each inlet; remove 
plug and inspectfor lime deposits and clean 
if necessary. This should be done once a 
year, more often if conditions warrant it. 

e) Remove gage glass and valves, and inspect 
these connections lime deposits and clean 
if necessary. This should be done once a 
year, more often if conditions warrant it. 

f) After inspection, replace glass (clean if 
necessary). Also inspect gage glass sealing 
washers and replace if necessary 

g) During cold weather, the historical boiler 
should be moved into a heated area and 
the boiler allowed to warm up in the air for 
several days until it is the same temperature 
as the air. 

h) The initial fire up should be done slowly to 
allow even heating of the boiler. 

i) Before movement, the cylinder(s) should 
be warmed up by allowing a small quantity 
of steam to blow through them and out the 



cylinder cocks and exhaust passage(s). This 
is necessary to reduce the stress in the cast- 
ing from thermal expansion of the metal. 

j) Steam should be discharged through the 
cylinder cocks for several minutes to aid 
removal of any solvent, debris, or rust that 
may have formed in the steam pipes, cyl- 
inder, valve chest, and dry pipe. 

k) All appliances should be tested under 
steam pressure before the historical boiler 
is moved or put under load. 



S2.14 



SAFETY PROCEDURES 3 



This chapter of text covers procedures if certain 
situations or emergencies that may occur. 



S2.14.1 



EXPERIENCE 



a) Reading check lists and procedures can be 
of some value to get you thinking about 
what you are doing, but nothing can re- 
place the experience gained by working 
beside conscientious and knowledgeable 
engineers. Ask questions, observe, read, 
listen, study, and think. 

b) Safe operations depend upon thorough at- 
tention to detailed routines. Having proce- 
dures thought out, planned, and practiced 
before they are needed could minimize 
accidents and improve public safety. Know 
your abilities as well as the machine's limi- 
tations that you are operating. In most cases 
knowing and keeping your machine in top 
operating condition can prevent most emer- 
gency situations from occurring. However, 
sometimes problems or situations beyond 
your control do occur. In any situation the 
first rule to remember is to keep a cool 



3 Copyright © 2004 Wisconsin Historical Steam Engine As- 
sociation. All rights reserved. The material in this text written 
by the Wisconsin Historical Steam Engine Association may not 
be reproduced in any form without written permission of the 
author and the Wisconsin Historical Steam Engine Association. 



1 53 



NATIONAL BPARD INSPECTION CODE • PART 2 — INSPECTION 



head. Haste and panic can never solve any 
emergency. 

c) Don't be afraid to ask for help or advice. A 
lot of shows or public demonstrations are 
having a designated individual in the area 
to ensure safe operation and assistance 
should a problem arise. 



S2.14.2 STOPPING ENGINE IN AN 
EMERGENCY 

a) Know how to stop your engine suddenly. 
For example, if someone or something runs 
out in front of you or some problem hap- 
pens with whatever you're belted up to: 

1) Close throttle. 

2) Reverse valve quadrant position. 

3) Open throttle for a moment (this will 
quickly stop your engine). 

4) Close throttle. 

5) Open cylinder cocks. 

b) Steam traction engines do not have brakes, 
so this is a maneuver worth knowing and 
practicing. However, it should be practiced 
with the dome valve shut. As this method 
of stopping your engine tends to be very 
hard on gears and castings! In regards to 
belt work, it is extremely important that you 
give your total undivided attention to what 
you are belted up to! Be prepared to shut 
down quickly should something happen, 
you are supplying the power to what you 
are running. Only you can stop the power! 
Be Alert! 



S2.14.3 WATER GLASS BREAKAGE 

This can be avoided by having a properly guard- 
ed water glass to prevent objects from coming 
in contact with the glass itself. However, water 



glasses do break. If your machine is operating 
when a break occurs: 

a) Close throttle. 

b) Set valve quadrant to neutral (middle 
notch). 

c) Disengage clutch. 

d) Close damper. 

e) Locate bottom water glass valve and shut 
off. 

1) The first four procedures will be difficult 
if your water glass is mounted back by 
the operator's platform. 

2) The bottom water glass valve is essential 
to locate and close first. This valve is 
below the waterline and can take the 
water dangerously close to the crown- 
sheet if water is allowed to escape 
unchecked. This is where having the 
automatic type gage valves would be 
most desirable. Most traction engines 
do not have automatic type gage valves. 
Caution must be exercised at this time 
because 300 degree steam and water 
will be spraying in every direction! You 
won't be able to see much of anything 
except a cloud of water vapor, so use a 
shovel or a coat or something to deflect 
the spray so you can find that lower 
valve. 

f) Next, close the top gage valve, this one 
should just be blowing steam and obscuring 
visibility. There is no serious problem with 
steam being released because this valve is 
above the water line. 

g) Next, use try cocks to determine water level 
of boiler. If bottom try cock blows water, 
then you can inject water and move to re- 
place water glass. However, if bottom try 
cock does not blow water, and only blows 
steam, do not inject water and proceed to 



1 54 



NATIDNAL BOARD INSPECTION CODE • PART 2 



INSPECTION 



kill fire immediately! Do not move engine! 
Another method of determ i n i ng you r water 
level in the boiler other than your try cocks 
is to wet down a burlap sack and lay it on 
the barrel part of the boiler. Quickly pull 
it away and you will see a "sweat line" of 
where your actual water level is. 



S2.14.4 RUNAWAY ENGINE AND 
GOVERNOR OVER SPEED 

a) Probable causes: governor malfunction. 
Most times the governor belt either slips 
or breaks. Know your governor belt condi- 
tion and keep its tension snug but not too 
tight. Also, packing nut could be too tight 
causing a binding on valve spindle, more 
often though this will cause engine to not 
respond to load and usually will not "run- 
away." 

b) What to do in a runaway situation: Again, 
I stress never leave the operator's platform 
while engine is at governed speed. In the 
case of a runaway engine: 

1) Quickly close the throttle. 

2) Move forward/reverse lever to center of 
quadrant. 

3) Open cylinder cocks. 

4) Close dome valve. 

5) Close damper and steam down (this is 
not a boiler emergency once engine has 
stopped there should be no danger). 

c) In the unlikely event the throttle was to 
jam in conjunction with governor malfunc- 
tion: 

1 ) Move forward/reverse lever to center 
of quadrant. This will stop the engine 
even though steam is still being sent to 
the valve chest. 



2) Close the dome valve; this would be the 
same as closing the throttle. Steam flow 
would then be stopped and the engine 
should be safe. 

3) Close damper and steam down. 



S2.14.5 KILLING A FIRE 

This is an important procedure to know, should 
a low water situation ever occur. 

a) Close all dampers. This will stop incoming 
air which supports fire. Capping the smoke- 
stack is also an additional way of checking 
draft to fire. However, it will cause a lot of 
smoke to emit around fire door. 

b) Shovel dry sand or dry earth on the fire, 
this should immediately cool the fire to a 
safe level. A good idea would be to have 
a pile of dry sand or dirt in or around your 
steam engine area should a situation occur. 
Also it is important to remember that when 
trying to extinguish fire, never stir the fire; 
this will only intensify the fire's heat. 

c) Close the fire door. 

d) Close the dome valve. 

e) Leave the engine alone. It is especially im- 
portant not to move the engine as this could 
slosh water onto a possibly overheated 
crownsheet. 



S2.14.6 INJECTOR PROBLEMS 

This is probably the number one problem oc- 
curring with boiler operation. An injector can 
be a very finicky device. Being able to identify 
the reasons why it's not working is one of the 
most important things a good steam engineer 
needs to know! Here are some various prob- 
lems and some of their causes. 



1 55 



NATIONAL BOARD INSPECTION CODE • PART 2 — INSPECTION 



a) Failure to raise water from supply tank 

1) Suction pipe clogged or tank supply 
valve turned off. 

2) Leaks in suction pipe or hose, allowing 
air to enter above the level of water 
supply. This is a common problem 
when rubber or plastic hoses are used 
on suction side of injector. 

3) Water supply too hot. Hot water will 
prevent injector from lifting water. 

4) Obstruction in the lifting or combining 
tubes of the injector. 

b) Injector lifts water but will not force it into 
the boiler 

1 ) Choked suction pipe or strainer/incom- 
plete obstruction. 

2) Supply valve not opened all the way. 

3) Boiler valve closed. 

4) Boiler check valve stuck closed. 

5) Obstruction in delivery tube on injec- 
tor. 

6) Leaking injector overflow check valve. 

7) Injector choked with lime. 

c) Some various injector problem scenarios 

1) In most cases you have a hot injector 
because of improper operation. This 
is where a removable rubber hose on 
your water suction is handy. Remove 
hose, turn steam valve on to injector 
and put your thumb over suction side 
of injector. You should feel a smooth 
steady suction. If not, wrap a rag around 
injector body and soak rag with cool 
water, your objective is to cool down 
the injector. Now turn steam back on to 



injector allowing cool air to suck into 
injector, at the same time place suction 
hose back onto water supply line and it 
should go. Remember to tighten suction 
side connections so you don't lose your 
vacuum. 

2) If injector still does not lift after trying 
the previous instructions, it probably 
has some foreign matter in the lifting or 
combining tube. Simply remove bottom 
square nut on injector body, taking care 
not to lose flat washer that will come 
out with injector combining tube, clean 
and reinstall. This should restore injec- 
tor to perfect working order. 

3) When having injector problems, watch 
your injector overflow. Steam only and 
no water at overflow usually is an in- 
dication of a water lifting problem (no 
water to the injector). Steam and water 
at the overflow is usually a delivery 
problem meaning your injector is lifting 
water but not forcing into boiler. 

4) The problem with delivery is usually 
associated with a stuck boiler check 
valve. After assuring yourself that the 
isolation valve to the boiler is open, 
try lightly tapping on the boiler check 
valve. More than likely though you will 
have to disassemble and clean boiler 
check valve, there is probably scale 
holding check valve from opening. This 
can be done with steam pressure on 
the boiler, providing the valve to the 
boiler holds pressure and the boiler 
check valve has been properly piped 
in. Much the same, a boiler check valve 
may not close, causing steam and hot 
water to blow back through injector 
and into your feedwater tank. Again, 
you would have to turn off the valve to 
the boiler, disassemble and clean the 
check valve. If the injector will not force 
water into the boiler, there may be an 
obstruction in the delivery/combining 
tube of the injector. Remove bottom nut 



1 56 



NATIONAL BOARD INSPECTION CODE • PART Z — INSPECTION 



of the injector, disassemble and clean 
as explained earlier. 



S2.14.7 FOAMING OR PRIMING BOILER 

a) As mentioned previously in this text, a 
foaming boiler is usually caused by dirty or 
impure water in the boiler. Oils, detergent, 
etc., are the biggest problems and have no 
business being on the waterside of a boiler. 
A good rule of thumb is "If you wouldn't 
drink it, don't put it in your boiler." Foaming 
can be especially bad because you have 
no way of discerning your water level. The 
water glass and try cocks will appear full. 
Foaming is usually really intensified with 
a heavy fire and a heavy engine load. The 
best thing you can do is to reduce or stop 
your engine load and reduce your fire until 
it settles down, steam down, wash out your 
boiler, and refill it with clean water. The first 
indication of a foaming or priming boiler 
is usually a "wet stack" and a discernable 
difference in the exhaust sound. Open cyl- 
inder cocks immediately and close throttle 
and discern your water level. 

b) Priming is much the same as foaming; 
you're pulling water into your engine. This 
is especially bad as this tends to wash the 
oil from valves and cylinders and you risk 
possible severe damage to the engine. 
Priming is caused more from carrying too 
high of a water level. It can also occur 
from working steam while ascending and 
descending hills. Again, know the machine 
you are operating, and what safe water 
level you must carry for the terrain you are 
traveling. 

c) If an engine starts priming (it will show a wet 
stack), open cylinder cocks, reduce throttle, 
get engine to level area, and discern water 
level. If you can, safely blowdown boiler to 
proper water level. Be sure no bystanders 
are close by for safety. 



S2.1 4.8 HANDHOLE GASKET BLOWS 
OUT 

a) Special care should be taken in assuring 
proper installation of handhole gaskets to 
prevent a blowout. 

b) New gaskets need special attention on the 
first fire-up. When installing, be sure plate 
surface and mating surface on boiler are 
free of loose scale and debris. Firmly snug 
the gasket after you have properly centered 
the gasket on the handhole, being careful 
not to over tighten as this tends to cut the 
gasket. One of the most common causes 
of handhole gasket blowout is improper 
fitting of gasket to handhole plate. It is very 
important that gasket fits center of handhole 
plate very snug. When steaming up care- 
fully "follow up" your gaskets by making 
sure nut stays snug. Special care must be ex- 
ercised here to make sure you don't rotate 
handhole plate or gasket. Caution should 
be used if boiler has any pressure built up 
on it. The best time to follow up on hand- 
hole gaskets is when steam is almost down 
after your first fire-up. It is important to snug 
them up before boiler cools, because as a 
boiler cools it will form a vacuum, and if 
your handholes are loose, they can suck in 
and drain your boiler. 

c) If a handhole gasket were to blow out: 

1 ) Close damper. Prepare to steam down. 
If you have a large fire, you might have 
to kill your fire. This all depends on how 
fast you are losing water and where 
on the boiler the handhole is leaking. 
Under no circumstance should you try 
and continue to operate engine! Peri- 
odic operation of the injector would be 
recommended to keep your water level 
up until you can get your fire down. 

2) Leave engine alone until steam is down. 
Carefully remove handhole plate and 
gasket. Inspect for cause of blowout. 



1 57 



NATIONAL BOARD INSPECTION CODE • PART 2 — INSPECTION 



S2.14.9 TUBE BURST 

Reason: Tubes will deteriorate and corrode over 
time. Usually a pit in the tube surface works its 
way through the tube and a pinhole develops. 
It's rare for a tube to actually "burst", usually 
just a small leak occurs. If the leak occurs on 
firebox end or if leak is a large one, it usually 
puts the fire out. Just leave the engine on a level 
surface and leave it alone. If the leak is toward 
the smoke box end of the boiler, you will no- 
tice water coming out the smoke box door. 
Again, watch your water level, close damper 
and prepare to steam down, or kill the fire if it 
hasn't done so already. This would depend on 
how fast you're losing water. Don't continue to 
operate the engine. 



S2.14.10 LEAKING VALVES 

Several reasons can cause a leaking valve. The 
most common would be a piece of scale or 
debris between valve seat and valve disc/plug. 
Another reason would be a break between 
valve stem and disc/plug (on a globe-type 
valve). Assuming scale on the valve seat, you 
can try opening and closing the valve to try 
and dislodge any debris. If the valve is broken 
or disc/plug has pulled off the end of the valve 
stem, usually there is nothing that can be safely 
done. Unless, you can isolate the valve by shut- 
ting off another valve further up the line. In most 
cases, determine how serious the valve leak is 
and determine if you are losing water and how 
fast, and then decide to either steam down or 
kill the fire. In most cases a normal steam down 
procedure is all that is required. 



S2.14.11 BROKEN PIPES 

Broken pipes on an engine should not occur if 
engine has been piped with proper materials 
and correct procedures have been followed. 
As previously mentioned in this text, close at- 
tention should be paid to pipe and pipe fittings 
and their condition! However, should a pipe 



or pipe fitting break, carefully try and locate a 
valve up-line and close valve to try and isolate 
the break. Then follow normal steam down 
procedures. If there is no valve up-line that can 
be shut off, assure safety of yourself and others 
around you by killing the fire immediately. 



S2.1 4.1 2 SAFETY VALVE PROBLEMS 

As mentioned earlier, testing of this critical 
safety device should be done each time your 
boiler is fired up. This is essential to assure its 
continued safe operation. In the event your 
safety valve does not open at its preset pressure 
and you have had no success trying to manually 
trip open valve lever, close your damper and 
follow steam down procedure. After closing 
damper, it would be wise to start your injector. 
This will decrease your steam pressure. Under 
no circumstance should the blowdown valve 
be used to release pressure (blowing down will 
lower your water level considerably). Killing 
the fire would not be necessary; providing your 
water level is at a safe level and your steam 
pressure is dropping from running the injector. 
Do not continue to run engine, remove the 
valve and send to a certified shop for repair or 
replace the valve. 



S2.14.13 SAFETY VALVE OPENS BUT WILL 
NOT CLOSE 

This problem is more prevalent than valves that 
don't open. There is no immediate danger in a 
safety valve that won't close, as you are only 
losing steam. However, the noise would tend 
to be very annoying! Try to manually open the 
valve a few times under pressure. Hopefully, 
this will seat the valve. Quite often bringing 
your steam pressure down about 25 PSI or so 
will let the valve seat. If after dropping your 
pressure it still does not seat, it obviously has 
an obstruction in the valve or a binding in the 
action of the valve. Follow normal steam down 
procedure. Remove valve and send to a certi- 
fied shop for repairs or replace the valve. 



NATIONAL BOARD INSPECTION CODE • PART Z — INSPECTION 



S2.14.14 LEAKING PIPE PLUGS 

More than likely threads were not properly 
cleaned before installation or thread tape/seal- 
ant not properly applied. Under no circum- 
stance should plugs be tightened with boiler 
under pressure! Usually the leak is very small 
and does not mean any immediate danger. Fol- 
low normal steam down procedure. 



S2.14.15 MELTED GRATES 

a) Closing damper with a hot coal fire. This 
restricts air flow to the grates, although rare 
for a grate to melt from this, it is possible 
to warp or ruin a good set of grates. Grates 
need air flow to keep them cool. Closing 
damper all the way with a hot coal fire 
should only be done in an emergency. 

b) Carrying ashes too high in ash pan is prob- 
ably the biggest reason for melted grates. 
The hot coals in the ash pan touching the 
grates and the restricted air flow is going to 
damage the grates. In some cases a grate bar 
can entirely melt out leaving a huge hole in 
your fire bed and an intense fire burning in 
your ash pan. Follow normal steam down 
procedure. 



1 59 



NATIONAL BOARD INSPECTION CODE • PART Z — INSPECTION 



The National Board of Boiler and Pressure Vessel Inspectors 
INITIAL BOILER CERTIFICATION REPORT (Form C-1) 



JURISDICTION NO. 



MANUFACTURER 



BOILER INFORMATION 



OWNER 



OWNER ADDRESS 



YEAR BUILT 



OWNER CITY/STATE 



BOILER TYPE 



USER 



ENGINE NO. 



USER ADDRESS 



OTHER NO. 



USER CITY/STATE 



HEATING SURFACE 



OPERATOR & LICENSE NO. 



BARREL INFORMATION 


INSIDE DIAMETER 


SEAM TYPE 


TUBE SIZE/NUMBER 


SEAM EFFICIENCY (from Table C-7600) 


TENSILE STRENGTH OF SHELL 


MAXIMUM PITCH OF SEAM RIVETS 


MIN. THICKNESS OF SHELL 


JACKET FULLY REMOVED FOR INSP 


MIN. THICKNESS OF TUBESHEET 


MAWP OF BARREL (from Table C-7300) 



FIREBOX AND WRAPPER SHEET 



STAYBOLT DIAMETER (Base of Threads) OF THINNEST STAYBOLT 



STAYBOLT PITCH (Max) AT CROWNSHEET 



TYPE OF STAYBOLT (Telltale?) 



MINIMUM THICKNESS OF STAYED SURFACE 



MAWP OF STAYED SURFACES (from Table C-7400-1 ) 



TYPE OF BOTTOM (Ogee, Wet Bottom, etc.) 



CONDITION OF THREADED MOUNTING STUDS 



GRATES, GRATE SUPPORTS, DAMPERS, ASHPAN — SATISFACTORY? 



CLEANED FOR INSPECTION? 






UIPMENTANDCONT 



SAFETY VALVE (per S2.8.1 ) 



MANUFACTURER 



SET PRESSURE 






CAPACITY 



SIZE 



FUSIBLE PLUG (per S2. 8. 4) 



NEW "ASME" PLUG 



OLD PLUG REMOVED FOR CROWN INSPECTION? 



FEED METHODS 



INJECTOR(S) BRAND/SIZE 



PUMP 
TYPE 



PREHEATER 
TYPE 



WATER COLUMN 



DRAIN 



WATER LEVEL 
VERIFIED? 



GAGE GLASS (per S2.8.2) 



GUARD 



TYPE 



TRY-COCKS (per S2.8.3) 



NUMBER 



OPERABLE? 



PRESSURE GAGE (per S2.8.5) 



DIAL RANGE 



SYPHON TYPE 



1 SO 



NATIONAL BOARD INSPECTION CDDE • PART Z — INSPECTION 



INITIAL BOILER CERTIFICATION REPORT (Form C-1) continued 



VALVES AND PIPING (pe r S2 9 and 



MAIN STEAM (dome) VALVE 



MAIN STEAM PIPING 



_ 



THROTTLE VALVE 



PIPE NIPPLES AT SHELL 



FEEDLINE STOP VALVEfs) 



FEEDLINE CHECK VALVES 



FEEDWATER PIPING TO INJECTORS & PIPING 



BLOWDOWN PIPING 



STEAM PIPING TO INJECTORS & PIPING 



BLOWDOWN VALVES 



INJECTOR ISOLATION (steam & water) VALVES 



PIPING SUPPORTS 



BLOWER VALVE 



BLOWER PIPING 



•..>?". ■'•:■■■■ ■ ■'.■■.... ■••:■■.•.,'. : /. 



Misayit^ssgsK 



TING REPAIRS AND ALTE 



INTERNAL VISUAL INSPECTION FINDINGS 



MAWP CALCULATIONS USING ULTRASONIC THICKNESS MEASUREMENTS 



BARREL: P = (TS x Tmin x E)/(R X FS) [per Table S2.10.3] 



FIREBOX: P = (T 2 x S x C/Pitch Max 2 ) [per Table S2.10.4] 



HYDROSTATIC PRESSURE TEST ( per S2.6.1 ) 



TEST PRESSURE — PSI 



TEST DATE 



TEST TEMPERATURE - 



TEST PROBLEMS 



1 6 1 



NATIONAL BOARD INSPECTION CODE • PART 2 — INSPECTION 



INITIAL BOILER CERTIFICATION REPORT (Form C-1) continued 



ABSENCE OF LEAKS 



OPERATING INSPECTION AT PRESSURE 



TEST OF INJECTOR(S) & PUMP (if used) 



TEST OF TRY-COCKS 



OPERATION OF THROTTLE & GOVERNOR 



TEST OF BLOWDOWN VALVE 



TEST OF SAFETY VALVE(S) 



VALVE POPPING POINT & BLOWDOWN 



^^^^p^^^^^^ ^^^^^ 



This form may be obtained from The National Board of Boiler and Pressure Vessel Inspectors, 1 055 Crupper Ave., Columbus, OH 43229 

1 62 



NB-405 Rev. 



NATIONAL BOARD INSPECTION CODE • PART Z — INSPECTION 



SUPPLEMENT 3 

INSPECTION OF GRAPHITE 
PRESSURE EQUIPMENT 



S3.1 



SCOPE 



a) The purpose of this supplement is to pro- 
vide requirements for inservice inspection 
of pressure equipment manufactured from 
impervious graphite materials. 

b) The impervious graphite (carbon, graph- 
ite, or graphite compound) used for the 
construction of graphite pressure vessels is 
a composite material, consisting of "raw" 
carbon or graphite that is impregnated with 
a resin using a tightly controlled pressure/ 
heat cycle(s). The interaction between the 
raw material and the resin is the determin- 
ing factor when considering the design 
characteristics of the material. The design 
characteristics include the strengths (flex- 
ural, compressive, and tensile), perme- 
ability, co-efficient of thermal expansion, 
thermal conductivity, and ultimately, the 
safe operating life of the vessel. 

c) The process used in the manufacturing of 
the raw material is well documented. The 
expertise developed in this field allows 
for many different grades to be manufac- 
tured to meet the specific needs of various 
industries, including corrosive chemical 
processing pressure vessels. In the chemi- 
cal processing industry the properties of the 
raw material are dictated by the Manufac- 
turer of the impregnated material, based 
on the pressure/temperature cycle and the 
type of resin used for impregnation. The 
raw material requirements are defined and 
communicated to the manufacturer of the 
raw material. The cycle and resin type may 
vary from manufacturer to manufacturer, 
and also for each "grade" of impregnated 
material a manufacturer produces. 

d) With over a century of experience with 
graphite pressure equipment, the essential 
variables of the process have been defined 



and apply universally to all manufacturers 
of impervious graphite equipment. There- 
fore, by requiring the essential variables of 
the resin impregnation cycle to be identi- 
fied and verified, it is possible to assign a 
"lot" number to all certified materials at 
completion of the resin impregnation pro- 
cess. This can be done with the assurance 
of meaningful and consistent test results. 



S3.2 



APPLICATION 



Due to inherent resistance to chemical attack, 
graphite pressure equipment is often used in 
corrosive applications, which may include 
lethal service. 



S3.3 



OPERATIONS 



The owner should maintain controlled condi- 
tions for use of graphite pressure equipment, 
including the use of temperature and pressure 
recorders and/or operating logs. The owner 
should maintain operating procedures, and 
ensure that pressure and temperature are con- 
trolled. A thermal or pressure spike may dam- 
age the graphite or metal components. 



S3.4 



INSERVICE INSPECTION 



a) The guidelines provided in Section 1 of this 
Part shall apply to graphite pressure equip- 
ment, except as modified herein. 

b) Graphite pressure vessels, pressure parts, 
and vessel components should receive an 
external visual examination biennially. All 
accessible surfaces should be chemically 
cleaned. Cleaning fluids containing strong 
oxidants should not be used. 

c) Typical indicators that should necessitate 
graphite pressure equipment inspection, 
evaluation, and repair include: 

1) Cross contamination of either process 
or service fluids; 



1 S3 



NATIONAL BOARD INSPECTION CODE • PART 2 — INSPECTION 



2) External leakage is observed; 

3) Flow rate is reduced or excessive pres- 
sure drop is observed; and 

4) Heat transfer performance is reduced. 

d) Cracks, bulges, blisters, delaminations, 
spalling conditions, and excessive erosion 
are cause for repair or replacement. Any 
surface discoloration should be recleaned 
and examined more closely to determine if a 
delamination or spalling condition exists. 

e) Other typical discontinuities include 
chipping, erosion, baffle cutting due to 
vibration, and cement deterioration. All 
passageways are susceptible to fouling. 



1 64 



NATIONAL BOARD INSPECTION CODE • PART 2 



INSPECTION 



SUPPLEMENT 4 

INSPECTION OF FIBER- 
REINFORCED THERMOSETTING 
PLASTIC PRESSURE EQUIPMENT 



S4. 



SCOPE 



This supplement provides specific guidelines 
for inspection of fiber-reinforced thermosetting 
plastic pressure equipment. 



S4.2 



INSERVICE INSPECTION 



Section 1 of this Part shall apply to inspection of 
fiber-reinforced plastic (FRP) equipment, except 
as modified herein. This supplement covers 
vessels and tanks only and was not written to 
cover piping and ductwork, although some of 
the information contained herein may be used 
for the inspection of piping and ductwork. 



S4.3 



GENERAL 



b) 



Typical FRP equipment consists of the struc- 
tural laminate (pressure-retaining material) 
and a liner (corrosion barrier) to protect 
the structural laminate, see Figure S4.3. 
The structural laminate is defined as one 
or more layers of reinforced resin material 
bonded together. In addition to damage 
from mechanical sources, FRP material 
may be susceptible to damage from acids, 
alkalis, compounds containing fluorine, 
solvents, and hot, clean water. 

For equipment fabricated with a liner, the 
primary purpose of a process side inspec- 
tion is to assure the integrity of the liner to 
prevent chemical attack and degradation 
of the structural laminate. For equipment 
fabricated without a liner, the purpose of a 
process side inspection is to determine the 
■ condition of the structural laminate. 



c) In addition to chemical attack, the laminate 
is also susceptible to damage from: 

1 ) excessive service temperatures; 

2) mechanical or service abuse; and 

3) ultra-violet light (See S4.7.2 [a]). 



S4.4 



VISUAL EXAMINATION 



a) Exposed surfaces shall be visually ex- 
amined for defects, and mechanical or 
environmental damage in the liner or the 
laminate. Classification and acceptance of 
any defects in the liner or laminate shall be 
according to Part 3, Repairs and Alterations, 
TableS4.12. 

b) Defects to look for include: 

1 ) Cracks 

2) Separation of secondary edges 

3) Leaks, especially around nozzles 



Figure S4.3 
Typical Vessel Shell 



Laminate " 




a 


= inner most layer 


b 


— interior layer 


c 


= structural laminate 


a + b 


= corrosion barrier (liner) 



1 65 



NATIONAL BOARD INSPECTION CODE • PART 2 — INSPECTION 



4) Discolored areas 

5) Areas of mechanical damage, such as 
impacts or gouges 

6) Surface deterioration; fiber exposure 

7) Cracked or broken attachments 

8) Damage due to dynamic loading 

9) Defective supports 

10) Delaminations 

11) Blisters 



S4.5 



INSPECTOR QUALIFICATIONS 



The "R" Stampholder's inspector shall have the 
following qualifications: 

a) No fewer than five years of current verifi- 
able documented experience in an occupa- 
tional function that has a direct relationship 
to reinforced thermoplastic (RTP) fabrica- 
tion and inspection, following customer or 
national standards, and be directly involved 
in the following activities: 

1) the development of plans, drawings, 
procedures, inspection requirements, 
acceptance criteria, and personnel 
qualification requirements; 

2) fabrication, construction, and supervi- 
sion of personnel in the production of 
assemblies or subassemblies; 

3) detection and measurement of non- 
conformities by application of visual 
or other nondestructive evaluation 
processes to written procedures; 

4) supervision of personnel engaged in 
material and component examination; 

5) repairs of equipment or supervision of 
personnel performing repairs; 



6) preparation of written procedures for 
assembly, acceptance, nondestructive 
evaluation, or destructive tests; 

7) qualification of secondary bonders, 
laminators, and welders to applicable 
codes, standards, or specifications; 

8) operation techniques or activities used 
to fulfill quality control requirements 
for RTP fabrication or assembly; and 

9) train the occupational skills of fabrica- 
tion or assembly of RTP equipment. 

b) The inspector shall meet the following vi- 
sual and educational requirements: 

1) be able to read a Jaeger Type No. 1 
standard chart at a distance of not less 
than 12 inches (305 mm); 

2) be capable of distinguishing and dif- 
ferentiating contrast between colors; 

3) have visual acuity checked annually 
to assure natural or corrected near dis- 
tance vision; and 

4) be a high school graduate or hold a 
state or military approved high school 
equivalency diploma. 

c) The employer of the inspector shall certify 
that the employee complies with the above 
qualification requirements. 



S4.6 



ASSESSMENT OF INSTALLATION 



An observation shall be made of the condition 
of the complete installation. 



S4.6.1 



PREPARATION 



An observation shall be made of the condi- 
tion of the complete installation, including 
maintenance and operation, as a guide in 
forming an opinion of the care the equipment 



1 66 



NATIONAL BOARD INSPECTION CODE • PART Z — INSPECTION 



receives. The history of the equipment shall S4.7.1 
be established, and shall include: date built, 
service history, maintenance, and a review of 
previous inspection records. Process conditions 
shall be reviewed to identify areas most likely 
to be attacked. Surface cleaning procedures and 
requirements shall also be reviewed. 



INSULATION OR OTHER 
COVERINGS 



S4.6.2 



LEAKAGE 



Any leak shall be thoroughly investigated and 
corrective action initiated. Repairs shall be 
in accordance with NBIC Part 3, Repairs and 
Alterations, Supplement 4, Repair and Altera- 
tion of Fiber-Reinforced Thermosetting Plastic 
Pressure Equipment. 



S4.6.3 TOOLS 

The following tools may be required by the 
inspector: 

a) Adequate lighting including overall lighting 
and a portable lamp for close inspections. 

b) Handheld magnifying glass. 

c) Barcol hardness tester. 

d) Small pick or pen knife. 

e) Small quantity of acetone and cotton 
swabs. 

f) Camera with flash capability. 

g) Liquid penetrant testing kit. 



S4.7 



EXTERNAL INSPECTION 



An external inspection is performed to de- 
termine if FRPs are in a condition to operate 
safely. 



It is not necessary to remove insulation and 
corrosion resistant covers for examination 
of the pressure equipment, if the coverings 
show no sign of mechanical impact, gouging, 
scratching, leaks, etc., and there is no reason 
to suspect any unsafe condition behind them. 
Where insulation coverings are impervious, 
such as a sealed fiberglass jacket, it is recom- 
mended that weep or drain holes be installed at 
the bottom of the insulation jacket as a means 
to detect leakage. 



S4.7.2 



EXPOSED SURFACES 



a) Exposed surfaces of pressure equipment 
are subject to mechanical, thermal, and 
environmental damage. Exposed surfaces 
may show damage from impact, gouging, 
abrasion, scratching, temperature excur- 
sions, etc. Sunlit areas may be degraded 
by ultraviolet light with a resulting change 
in surface color and increased fiber promi- 
nence, but with no loss in physical proper- 
ties. Overheating may also cause a change 
in color. 

b) The location of external damage should be 
noted so that the opposing internal surface 
at that location can be examined. For ex- 
ample, an impact load applied to the outer 
surface may be transmitted through the 
laminate causing a star crack in the inner 
surface. See Figure S4.10-t. 

c) Areas that should be closely examined 
are: 

1) Nozzle attachments 

2) Gusset attachments 

3) Flanges 

4) Secondary joints 



1 67 



NATIONAL BOARD INSPECTION CODE • PART Z 



INSPECTION 



5) Hold down lugs 

6) Lifting lugs 

7) Attachments 



S4.7.3 



STRUCTURAL ATTACHMENTS 



a) Attachments of legs, saddles, skirts, or other 
components shall be examined for cracks 
where the component attaches to or con- 
tacts the vessel and the component itself. 
See Figure S4.10-r. 

b) Piping loads on nozzles may be excessive. 
Therefore, all nozzles shall be closely 
examined for cracks as shown in Figures 
S4.10-pandS4.10-cc. 



S4.8 



INTERNAL INSPECTION 



An internal inspection is performed to deter- 
mine the condition of internal surfaces and the 
pressure integrity of the item. 



S4.8.1 GENERAL 

FRP surfaces shall be dry and clean for the in- 
spection. Every effort shall be made to minimize 
damage to the liner during inspection. Defects 
to look for include: 

a) Indentations 

b) Cracks 

c) Porosity 

d) Exposed fibers 

e) Lack of resin 

f) Delaminations 

g) Thinning at points of fluid impingement 



h) Blisters 

i) Scratches 

j) Gouges 

k) Discolorations 



S4.8.2 



SPECIFIC AREAS OF CONCERN 



All surfaces shall be examined with both direct 
and oblique illumination. Color differences, 
opacity, stains, wetness, roughness, or any 
deviation from the original surface (original 
cutout sample) condition shall be noted and 
investigated. Liquid level lines shall be defined 
so the laminate condition in both the wet and 
dry zones can be determined. The following 
areas should be closely examined for cracks, 
porosity, or chemical attacks on the liner or 
laminate: 

a) Fittings 

b) Changes in shape 

c) Baffles 

d) Secondary overlays 

e) Nozzles 

f) Cut edges 

g) Supports/internal structures and areas of 
attachment 



S4.9 



INSPECTION FREQUENCY 



Frequency of inspections are established to 
determine how often inspections shall be 
performed to ensure safe operation of FRP 
equipment. 



1 SB 



NATIONAL BDARD INSPECTION CODE • PART 2 



INSPECTION 



S4.9.1 NEWLY INSTALLED EQUIPMENT c) FRP equipment should be internally in- 

spected: 

1 ) one year after the introduction of pro- 
cess fluid to establish any changes due 
to service and chemical environment; 

2) after the initial first year inspection, 
subsequent inspections are to be 
established based on those results. 
Subsequent inspection intervals shall 
be documented. It is suggested to docu- 
ment inspections using photographs; 

3) when some conditions may exist where 
entry is prohibited and alternate means 
of inspection considered; 



a) The following factors should be consid- 
ered when determining the frequency of 
inspection of FRP equipment that is new 
and recently placed into service. 

1) The distance between the FRP equip- 
ment and personnel or critical equip- 
ment. 

2) Substance contained in the vessel is of 
such a nature that if abruptly released 
it could threaten the health or safety of 
personnel. 

3) Contains chemicals or is subject to 
conditions known to degrade or shorten 
the life of FRP laminates. 

4) Past experience has shown that the 
service application warrants more 
frequent internal and external inspec- 
tions. 

5) Insurance or jurisdictional require- 
ments. 

b) FRP equipment should be externally in- 
spected: 



4) if prior experience (i.e., if equipment 
was recently replaced using same 
material/construction) dictates that 
inspection frequency other than that 
documented is acceptable, then the 
inspection frequency may be altered; 
or 

5) if upsets outside the vessel design con- 
ditions in the process occur, internal 
inspections shall be performed to en- 
sure equipment integrity. 



1 ) once every 2 to 3 years after introduc- 
tion of process fluid. All findings are 
to be documented in the equipment 
inspection file for comparison to future 
inspection; 

2) if upsets outside the vessel design con- 
ditions in the process occur, external 
inspections shall be performed to en- 
sure equipment integrity; or 

3) if prior experience (i.e., if equipment 
was recently replaced using same mate- 
rial/construction) dictates that inspec- 
tion frequency other than that listed is 
acceptable (through previous inspec- 
tions and records), then the inspection 
frequency may be altered. 



S4.9.2 PREVIOUSLY REPAIRED OR 

ALTERED EQUIPMENT 

a) The following factors should be considered 
when determining the frequency of inspec- 
tion for FRP equipment. 

1) The distance between the FRP equip- 
ment and personnel or critical equip- 
ment. 

2) Substance contained in the vessel is of 
such a nature that if abruptly released 
it could threaten the health or safety of 
personnel. 



1 69 



NATIONAL BOARD INSPECTION CODE • PART Z 



INSPECTION 



3) Contains chemicals or is subject to 
conditions known to degrade or shorten 
the life of FRP laminates. 

4) Past experience has shown that the ser- 
vice application warrants more frequent 
internal and external inspections. 

5) Insurance or jurisdictional require- 
ments. 

b) FRP equipment should be externally in- 
spected: 

1) annually — all findings are to be docu- 
mented in the equipment inspection file 
for comparison to future inspection; 

2) if upsets outside the vessel design con- 
ditions in the process occur, external 
inspections need be performed to en- 
sure equipment integrity; and 

3) if prior experience (i.e., if equipment 
was recently replaced using same mate- 
rial/construction) dictates that inspec- 
tion frequency other than that listed is 
acceptable (through previous inspec- 
tions and records), then the inspection 
frequency may be altered. 

c) FRP equipment should be internally in- 
spected: 

1 ) one year after the introduction of pro- 
cess fluid to establish any changes due 
to service and chemical environment; 

2) if upsets outside the vessel design 
conditions in the process occur, inter- 
nal inspections need be performed to 
ensure equipment integrity; 



4) If prior experience (i.e., if equipment 
was recently replaced using same mate- 
rial/construction) dictates that inspec- 
tion frequency other than that listed is 
acceptable (through previous inspec- 
tions and records), then the inspection 
frequency may be altered; and 

5) some conditions may exist where entry 
is prohibited and alternate means of 
inspection must be considered. 



S4.1 PHOTOGRAPHS OF TYPICAL 

CONDITIONS 

The following pages contain photographs of 
typical conditions that may exist in inservice 
FRP vessels and piping. These surface condi- 
tions can be similar to or different from those 
encountered in practice. Also, differing causes 
of surface degradation can result in similar 
surface appearances. 

Note: Figures S4.10-J through 54.10-u were 
reprinted with permission of the Copyright 
Owner. ©MATERIALS TECHNOLOGY INSTI- 
TUTE, INC. (2002). The captions of the figures 
were revised by the NFJIC Committee. 



3) based on the initial first year inspection, 
subsequent inspections are to be es- 
tablished based on those documented 
results and the results documented. It 
is suggested to document the interior 
inspection using photographs; 



1 7D 



NATIONAL BOARD INSPECTION CODE " PART 2 — INSPECTION 



Figure S4.10-a 

Excessive Heat. Possible causes are localized high 

temperature excursions. 




Figure S4.10-b 

Laminate Voids at Overlays. 




voids 



1 7 1 



NATIDNAL BOARD INSPECTION CODE • PART 2 — INSPECTION 



Figure S4.10-C 

Surface Deteriorations. Possible causes are exposure 

to hot water and/or steam and chemical attack. 




Figure S4.10-d 

Blisters. Possible cause is exposure to steam or 

purified hot water. 



mm 



WSB&&im 



1 72 



NATIONAL BOARD INSPECTION CODE • PART 2 — INSPECTION 



Figure S4.10-e 

Surface Erosion. Possible causes are high flow rate of 
fluids, erosion due to particulates in fluid, and chemical 
attach/softening of resin. 



izpiigalli 



surface erosion 



Figure S4.10-f 
Corrosion/Erosion. 




1 73 



NATIONAL BDARD INSPECTION CODE • PART 2 — INSPECTION 



Figure S4.10-g 

Cracks. Possible cause is impact from an 

external source. 



■ 



it 



11111 

ISPS 

mams' 

mm 



u'Ss! 



Figure S4.10-h 

Corrosion (Loss of Veil) 



: 



•-— -^-— • ^■™ ■ ■■«■ 



iBIiiiHlMlpl^^WStisWll 



MasHnnHP 

InHHHBRi 



SI 






JMlifc 



ill 



■e^s 



1 74 



NATIONAL BOARD INSPECTION CODE • PART 2 — INSPECTION 



Figure $4.1 0-i 

Shell Fracture. Possible cause is exterior impact 







Figure S4.10-J 

Concentrated Sulfuric Acid Attack. 



Ufa 



WMSmBBSRBMm 




1 75 



NATIONAL BOARD INSPECTION CODE • PART 2 — INSPECTION 



Figure S4.1G-k 
Blister. 



'***?»«*, 



*H8P 
m|H9s 



mm® 



wm 
Wmm 

mm 
illfil 






%»& 



JHHHl 



Figure S4.10-I 

Fiber Prominence. Possible cause is exposure to sunlight 

and no UV protection. 



i', : V.-V".f: -:,, ' . ''V*. * V. ... **.~ '* ■ ' •■ . , " ^ ' ■ 




iipTOflHi 




Kips '.< •, • 




ill 


-""" 


HH||S 

Hi ■.::■■.:..:■■ ■■■: ■■.:■ 

■np^^^Iitte" : ISi^ tit 






^^RJlif' ^",'i 






HHh|^hh^^^.^s^V. ,. : l|§tti j : s 








MHHaiMNNSHBHHBHBHHHRlHHi 


r.--iv.:\«5*J.^.^: 



1 76 



NATIONAL BDARD INSPECTION CODE • PART 2 — INSPECTION 



Figure S4.10-m 
Color Change. 



^gjjffism 




(mgmimmmiiBm 




CHR V.I ' 4Cif 

8C)3t.fN6 Water 
HYDROCHLORIC AG tO 



Figure S4.10-n 

Cut Edge Evaluation. 




1 77 



NATIONAL BOARD INSPECTION CODE • PART Z — INSPECTION 



Figure S4.10-O 
Erosion in the Liner. 




Figure S4.10-p 

Cracked Flange. Possible causes are incorrect match up 

of flanges, over torque of bolts at fit up, manufacturing 

defect, or excessive piping loads. 







■ 




1 7B 



NATIONAL BOARD INSPECTION CODE • PART 2 — INSPECTION 



Figure S4.10-q 

Gouge. Possible cause is mechanical damage. 




Figure S4.10-r 

Gusset Crack. Possible causes are excessive load due to 
unsupported valve, pipe, or overstress and age. 




1 79 



NATIONAL BOARD INSPECTION CODE - PART Z — INSPECTION 



Figure S4.10-S 

Cracks at the Knuckle. Possible cause is inadequate 

anchoring of vessel. 



msBSMssm 



WBmm 

BHHffilfi! 

WBBm 
■hShHw!S$ 



m mbm 



Figure §4.1 0-t 

Star Craze in Corroded Liner. Possible cause is 

external impact. 







i •■.■'.- ;■'*&?£ 
I ■■ ■ 'jA-^i 

'■* i 

■-■•- ■■■-■.-: 



-•'■: 






vB,;f. ." 






S^P^^ 



1 3D 



NATIONAL BOARD INSPECTION CODE • PART 2 — INSPECTION 



Figure S4.10-U 

Sulfuric Acid Attack and Thermal Shock. 



If 



its 
Ill 




ilS 



: il!SI!IIP|liiill 




Figure S4.10-V 

Air Bubbles Behind the Veil (shown after 

chemical exposure). 




i a i 



NATIONAL BOARD INSPECTION CODE • PART Z — INSPECTION 



Figure S4.10-W 

Delaminations and Blisters. Possible causes are exposure 
to high heat or improper surface preparation of liner prior 
to structural application. 




Figure S4.10-X 
Flange Cracking. 





i sz 



NATIONAL BOARD INSPECTION CODE • PART Z INSPECTION 



Figure S4.10-y 

Elastomeric Gasket Extruding. Possible causes are 

excessive bolt torque or improper bolting sequence. 



WSBasSB^SSeSBBi 



^M 



salsKf 




l^i^^i 



*£* 



■iitjiip 



Figure S4.10-Z 

Incorrect Gusset Attachment. Possible causes are gussets 
not extending out from flange a minimum of 30° from the 
axis of nozzle neck or gusset attachments used as part of 
the flange thickness. 

■ m m ~ IF*" 




1 S3 



NATIONAL BOARD INSPECTION CODE • PART Z INSPECTION 



Figure S4.10-aa 

Star Craze. Possible cause is external impact. 




Figure S4.10-bb 
Excessive Use of Putty. 









§|ll|j| 


S 


^a^feaJa^Mpatoga 




j 






ttMMi 








'•■'■" 'VH& gji^vyv 






%£®$&mSim 


fc^^^^^^^Bl^P 








''<■■ ~;;H ,v-v v ', tf ^ - , 






fll^^^M 


O v; 










'-. .^ • j 














.,-..."'♦'.. '.'■'"" ■■■''■'. 3 


, t 


iiijuii 




iimpsi 








A« ■ 


'""\ ■'.-'. ,1 

.'•■-. *i 

- '--I 

.. -. .. j 

""- f 

1111111 

sllll 



1 84 



NATIONAL BOARD INSPECTION CODE • PART Z — INSPECTION 



Figure S4.10-cc 

Cracked Flange. Possible cause is bolting dissimilar flanges 

together (full-faced flange with raised-face flange). 




cracks 



1 S5 



NATIONAL BOARD INSPECTION CODE • PART 2 



INSPECTION 



SUPPLEMENTS 

INSPECTION OF YANKEE 
DRYERS (ROTATING CAST- 
PRESSURE VESSELS) WITH 
FINISHED SHELL OUTER 
SURFACES 



RON 



S5.1 



SCOPE 



a) This supplement describes guidelines for 
the inservice inspection of a Yankee dryer. 
A Yankee dryer is a rotating steam-pres- 
surized cylindrical vessel commonly used 
in the paper industry, and is made of cast 
iron, finished to a high surface quality, and 
characterized by a center shaft connecting 
the heads. 

b) Yankee dryers are primarily used in the 
production of tissue-type paper products. 
When used to produce machine-glazed 
(MG) paper, the dryer is termed an MG 
cylinder. A wet paper web is pressed onto 
the finished dryer surface using one or 
two pressure (pressing) rolls. Paper is dried 
through a combination of mechanical 
dewatering by the pressure roll(s); thermal 
drying by the pressurized Yankee dryer; and 
a steam-heated or fuel-fired hood. After 
drying, the paper web is removed from the 
dryer. 

c) The dryer is typically manufactured in a 
range of outside diameters from 8 to 23 
ft. (2.4 m to 7 m), widths from 8 to 28 ft. 
(2.4 m to 8.5 m), pressurized and heated 
with steam up to 1 60 psi (1 1 00 kPa), and 
rotated at speeds up to 7000 ft./min (2135 
m/min). Typical pressure roll loads against 
the Yankee dryer are up to 600 pounds per 
lineal inch (105 kN/m). A thermal load 
results from the drying process due to dif- 
ference in temperature between internal 
and external shell surfaces. The dryer has 



an internal system to remove steam and 
condensate. These vessels can weigh up to 
220 tons (200 tonnes). 

d) The typical Yankee dryer is an assembly of 
several large castings. The shell is normally 
a gray iron casting, in accordance with 
ASME designation SA-278. Shells internally 
may be smooth bore or ribbed. Heads, 
center shafts, and journals may be gray cast 
iron, ductile cast iron, or steel. 



S5.2 



ASSESSMENT OF INSTALLATION 



a) The Inspector verifies that the owner or user 
is properly controlling the operating condi- 
tions of the dryer. The Inspector does this 
by reviewing the owner's comprehensive 
assessments of the complete installation, 
operating environment, maintenance, and 
operating history. 

b) The dryer is subjected to a variety of loads 
over its life. Some of the loads exist indi- 
vidually, while others are combined. Con- 
sideration of all the loads that can exist on a 
Yankee dryer are required to determine the 
maximum allowable operating parameters. 
There are four loads that combine during 
normal operation to create the maximum 
operating stresses, usually on the outside 
surface of the shell at the axial center line. 
These are: 

1) Pressure load due to internal steam 
pressure; 

2) Inertial load due to dryer rotation; 

3) Thermal gradient load due to the drying 
of the web; and 



i as 



NATIONAL BOARD INSPECTION CODE • PART Z — INSPECTION 



FIGURE S5.2 



"' 



) Cross section of 
{ internal grooving 
\ of shell 



JINL 






-.ytf^'/RE^LifiE - P';-l ItjPI- 



-^S 



'/: 



'{O.ROO O.7U0 (;. K 0(1 0.9 .10 

I i i i i-'i i i i i i i m i i i i r 

i 5 / 20 

ROOT SHELL THICKNESS fl 

L - END LIFE THICKNESS 



;n;.:Cv 



Mill j"! "■}■■! — | — 1 — | — T I I |,i | I | I j l 



;sr;f cut oft 



SUPPLIED ROCi! 
THICKNESS 



4) Pressure roll load (line or nip load) 4 
due to pressing the wet web onto the 
dryer. 



4 Pressure roll load, line load, and nip load are terms thai 
are used interchangeably to refer to the interaction between 
the pressure roll(s) and the Yankee dryer. It is called "nip" load 
because the pressure roll is rubber-covered and is pressed up 
against the Yankee with enough force to create a nip (or pinch) 
that forces the paper into line contact between the rolls and 
provides some mechanical dewatering. The paper then sticks 
onto the Yankee surface and follows the Yankee dryer for ther- 
mal dewatering by the steam-heated Yankee surface. This "nip 
load" is called a "line load" because the units are load (force) 
per length of line contact. The units are pounds per linear inch 
(PLI) and kiloNewtons per meter (kN/m). 



c) Steam pressure, inertial, and thermal gra- 
dient loads impose steady-state stresses. 
These stresses typically change when the 
dryer shell thickness (effective thickness 
for ribbed dryers) is reduced to restore a 
paper-making surface, the grade of tissue is 
changed or speed of the dryer is changed. 

d) The pressure roll(s) load imposes an alter- 
nating stress on the shell face. The resulting 
maximum stress is dependent on the mag- 
nitude of the alternating and steady-state 
stresses. 



1 B7 



NATIONAL BOARD INSPECTION CODE • PART 2 



INSPECTION 



e) Section VIII, Div. 1, of the ASME Code 
only provides specific requirements for 
the analysis of pressure loads. Although 
the Code requires analysis of other loads, 
no specific guidance for thermal, inertial, 
or pressure roll loads is provided. Hence, 
additional criteria must be applied by the 
manufacturer to account for all the steady- 
state and alternating stresses. 

f) To maintain product quality, the dryer sur- 
face is periodically refurbished by grinding. 
This results in shell thickness reduction. 
Therefore, the manufacturer does not 
provide a single set of maximum allow- 
able operating parameters relating steam 
pressure, rotational speed, and pressure 
roll load for a single design shell thickness. 
The manufacturer, or another qualified 
source acceptable to the Inspector, instead 
provides a series of curves that graphically 
defines these maximum allowable oper- 
ating parameters across a range of shell 
thicknesses. This document is known as the 
"De-rate Curve." See Figure S5.2. 

g) In addition to the loads on the dryer due to 
normal operation, other nonstandard load 
events can occur. These nonstandard load 
events should be recorded in an operation 
or maintenance log. Examples of nonstan- 
dard load events include: 

1 ) Excessive thermal load due to local or 
global heating rate during warm-up; 

2) Excessive thermal load due to local or 
global cooling rate during shut-down; 

3) Excessive thermal load due to inappro- 
priate use or malfunctioning auxiliary 
heating devices causing localized heat- 
ing; 

4) Excessive thermal load due to the mis- 
application or uncontrolled application 
of water or other fluids for production, 
cleaning, or fire fighting; and 

5) Impact load. 



h) If nonstandard load events have occurred, 
then the Inspector should ensure that an 
appropriate assessment of the structural in- 
tegrity on the dryer has been performed. 



S5.2.1 DETERMINATION OF 

ALLOWABLE OPERATING 
PARAMETERS 

a) A Yankee dryer is designed and intended 
to have its shell thickness reduced over the 
life of the vessel through routine wear and 
grinding. The Yankee dryer shell is ground 
on the outside surface to restore the qual- 
ity or shape of the papermaking surface, 
essential to the manufacturing of tissue or 
other paper products. 

b) Design documentation is required that 
dictates the maximum allowable operating 
parameters as shell thickness is reduced. 
Calculations used to determine those 
parameters are in accordance with ASME 
Code requirements for primary membrane 
stress and design criteria based upon other 
relevant stress categories; e.g., fatigue and 
maximum principal stress. Calculation of 
these parameters requires that the respec- 
tive stresses, resulting from the imposed 
loads, be compared to the appropriate 
material strength properties. Hence, knowl- 
edge of the applied stresses in the shell and 
the tensile and fatigue properties of the 
material are essential. 

c) Yankee dryers are subjected to a variety 
of loads that create several categories of 
stress. Yankee dryers are designed such 
that the stress of greatest concern typically 
occurs on the outside surface at the axial 
centerline of the shell. 

1) Steam Pressure Load — The internal 
steam pressure is one of the principal 
design loads applied to the Yankee 
dryer. The steam pressure expands the 
shell radially, causing a predominately 
circumferential membrane tensile 



1 8B 



NATIONAL BPARD INSPECTION CODE • PART 2 



INSPECTION 



stress. Because the shell is constrained 
radially by the heads at either end of the 
shell, the steam pressure also causes a 
primary bending stress in the vicinity of 
the head-to-shell joint. The ends of the 
shell are in tension on the inside and 
compression on the outside due to the 
steam pressure. The steam pressure also 
causes a bending stress in the heads. 

2) Inertia Load — The rotation of the 
Yankee dryer causes a circumferential 
membrane stress in the shell similar to 
that caused by the steam pressure load. 
This stress is included in the design 
of the shell and increases with dryer 
diameter and speed. 

3) Thermal Gradient Load — The wet 
sheet, applied to the shell, causes the 
outside surface to cool and creates 
a thermal gradient through the shell 
wall. This thermal gradient results in the 
outside surface being in tension and the 
inside surface in compression. With this 
cooling, the average shell temperature 
is less than the head temperature, which 
creates bending stresses on the ends of 
the shell and in the heads. The ends of 
the shell are in tension on the outside 
and compression on the inside. 

a. Other thermal loading also occurs 
on a Yankee. The use of full width 
showers for a variety of papermak- 
ing purposes affects the shell simi- 
lar to a wet sheet. The use of edge 
sprays produce high bending stress 
in the ends of the shell due to the 
mechanical restraint of the heads. 

b. Warm-up, cool-down, hot air im- 
pingement from the hood, moisture 
profiling devices, fire fighting, and 
wash-up can all produce non-uni- 
form thermal stresses in the pres- 
sure-containing parts of the Yankee 
dryer. Heating or cooling different 



portions of the Yankee dryer at dif- 
ferent rates causes these non-uni- 
form stresses. 

4) Line Load — The line load from the 
contacting pressure roll(s), results in an 
alternating, high cycle, bending stress 
in the shell. This stress is greatest at 
the centerline of the shell. The load of 
the pressure roll deflects the shell radi- 
ally inward causing a circumferential 
compressive stress on the outside sur- 
face and a tensile stress on the inside. 
Because the shell has been deflected 
inward at the pressure roll nip, it bulges 
outward about 30 degrees on each side 
of the nip. The outward bulge causes a 
tensile stress on the outside shell sur- 
face at that location and a correspond- 
ing compressive stress on the inside. 
Since the shell is passing under the 
pressure roll, its surface is subjected to 
an alternating load every revolution. 



S5.2.2 ADJUSTING THE MAXIMUM 

ALLOWABLE OPERATING 
PARAMETERS OF THE YANKEE 
DRYER DUE TO A REDUCTION 
IN SHELL THICKNESS FROM 
GRINDING OR MACHINING 

a) The outside surface of the Yankee dryer shell 
is routinely ground to restore the quality of 
the papermaking surface. The papermaking 
surface degrades due to wear, corrosion, 
and local thinning. As the shell thickness is 
reduced, the maximum allowable operating 
parameters are adjusted. Adjustment of the 
maximum allowable operating parameters 
requires accurate shell thickness measure- 
ments. 

b) Over the life of the Yankee dryer, the adjust- 
ment of the maximum allowable operating 
parameters will require that the original 
design pressure and/or the pressure roll line 
load be reduced. After the maximum al- 



1 59 



NATIONAL BOARD INSPECTION CODE • PART Z 



INSPECTION 



lowable operating parameters are adjusted 
per the De-rate Curve, the appropriate load 
limiting devices are reset (e.g., steam safety 
relief valve, line load limiting device). 



S5.2.3 DOCUMENTATION OF SHELL 

THICKNESS AND ADJUSTED 
MAXIMUM ALLOWABLE 
OPERATING PARAMETERS 

a) Yankee dryers are designed and intended 
to have the shell thickness reduced over 
the life of the vessel as a result of routine 
wear and grinding. Yankee shell grinding is 
routinely performed to restore the quality 
or shape of the papermaking surface. 

b) Design documentation, a De-rate Curve, 
is required, which dictates the maximum 
allowable operating parameters, based on 
imposed loads over a range of shell thick- 
ness. The documentation shall be obtained 
from the original dryer manufacturer or 
from another qualified source acceptable 
to the Inspector. 

c) Yankee dryer shell grinding requires ac- 
curate shell thickness measurements in 
conjunction with the De-rate Curve in order 
to set load-limiting devices. The resulting 
shell thickness and maximum allowable 
operating parameters after grinding shall 
be documented, and the Inspector noti- 
fied that load-limiting device settings have 
changed. 



S5.3 CAUSES OF DETERIORATION 

AND DAMAGE 

Three types of deterioration or damage typi- 
cally encountered in Yankee dryers are local 
thinning, cracking, and corrosion. Many times 
the mechanisms are interrelated, one being the 
precursor of another. 



S5.3.1 



LOCAL THINNING 



a) Internally, a Local Thin Area (LTA) can occur 
on the pressure-retaining surfaces due to 
steam and condensate erosion, mechanical 
wear, and impact, and removal of material 
flaws. These assume features ranging from 
broad shallow areas washed-out by ero- 
sion, to more groove-like flaws, including 
gouges and indentations from contacting 
metal parts. 

b) Externally, the process is typically one of 
wear-corrosion in circumferential bands. 
Except on the shell edges, local thinning 
never achieves significant depth because 
the papermaking process will tolerate 
only the smallest departure from surface 
contour. On the shell edges, beyond the 
papermaking surface, wear-corrosion may 
advance to comparatively greater depths. 
However, the stresses are far less in this 
area than under the papermaking surface, 
so the wear is inconsequential in consider- 
ations of load-carrying ability. Only in the 
instance of steam leakage between flanges, 
has the resultant local thinning ever been 
implicated in Yankee failure. 

c) Steam leakage is detrimental to the long- 
term structural integrity of the vessel, in that 
the escaping steam, under high velocity, 
erodes ever-widening paths in the cast-iron 
surfaces over which it passes, thinning the 
cross section. Steam cutting of connecting 
bolts is another possible outcome. Either 
result reduces load-carrying capacity of the 
part. A safety hazard can also be created for 
operating personnel, who may be burned 
by the high velocity steam jets. 

d) Interface leakage, including joints and 
bolted connections. 

1 ) Joint Interface Corrosion 

Jacking forces, which develop from 
the expansion of corrosion products 
between head-to-shell flanges, cause 
flange separation and create leak- 



i go 



NATIONAL BOARD INSPECTION CODE • PART 2 — INSPECTION 



age paths between the flanges and/or 
through the bolt holes. 

2) Insufficient Joint Clamping Force 
Through inadequate design, improper 
assembly, loss of washer/gasket, or 
stress corrosion cracking of connect- 
ing bolts, the clamping force between 
mating flanges is insufficient to retain 
internal pressure. 

3) Washer/Casket Functional Loss 
Deterioration, caused by corrosion or 
expulsion, provides a path for escaping 
steam and condensate. 



b) 



down by Section VI 1 1 of the ASME Code and 
the safety factors inherent to the "De-rate 
Curve" calculated by the vessel manufac- 
turer or equally qualified source. Failure 
to maintain operation within the steam 
pressure established by those criteria can, 
in the extreme, lead to cracking. 

Pressure Roll Overload 
Included in Yankee Dryer shell design is a 
fatigue factor of safety. Exceeding allow- 
able roll load, in combination with other 
stress-elevating or strength-reducing condi- 
tions, can precipitate fatigue cracking and 
failure. 



4) Flange Machining Variation 

Variations in surface contour of flange 
faces may create leakage paths. 

e) Through-Wall Leakage 

Cast iron inherently exhibits shrinkage 
porosity. Where porosity linkages occur 
between internal and external surfaces, a 
path for steam leakage is made available. 
Such leakage is largely an operational issue, 
as holes are formed in the paper product, 
demanding expedient attention. 



S5.3.2 



CRACKING 



Cracks in cast-iron parts are problematic be- 
cause of the relatively low fracture toughness 
compared with standard, more ductile pressure 
vessel materials and because strengthening 
repair through welding is prohibited. Further- 
more, Yankee dryers are subject to both low- 
and high-cycle fatigue loading. Consequently, 
considerable emphasis is placed upon quality 
inspection for and timely remediation of cracks, 
the central causes of which (in Yankee dryers) 
are: 



S5.3.2.1 THROUGH JOINTS AND 
BOLTED CONNECTIONS 

a) Joint Interface Corrosion 

Jacking forces, which develop from the 
expansion of corrosion products between 
head-to-shell flanges, cause flange separa- 
tion and create leakage paths between the 
flanges and/or through the bolt holes. 

b) Insufficient Joint Clamping Force 
Through inadequate design, improper 
assembly, loss of washer/gasket, or stress 
corrosion cracking of connecting bolts, the 
clamping force between mating flanges is 
insufficient to retain internal pressure. 

c) Washer/Gasket Functional Loss 
Deterioration, caused by corrosion or ex- 
pulsion, provides a path for escaping steam 
and condensate. 

d) Flange Machining Variation 
Variations in surface contour of flange faces 
may create leakage paths. 



Overpressurization 

As shell thickness is routinely diminished 
through time, Yankee dryers are designed to 
operate within the pressure limitations set 



S5.3.2.2 THROUGH-WALL LEAKAGE 

Cast iron inherently exhibits shrinkage poros- 
ity. Where porosity linkages occur between 



1 9 i 



NATIONAL BOARD INSPECTION CODE e PART 2 



INSPECTION 



internal and external surfaces, a path for steam 
leakage is made available. Such leakage in the 
shell is largely an operational issue, as holes 
are formed in the paper product, demanding 
expedient attention. 



S5.3.2.3 IMPACT FROM OBJECTS 
PASSING THROUGH THE 
YANKEE/PRESSURE ROLL NIP 

Because of cast iron's low fracture toughness, 
it is especially intolerant of local, high impact 
loads. 



S5.3.2.4 STRESS MAGNIFICATION 
AROUND DRILLED HOLES 

Surface defects, caused by porosity and in- 
dentations, are frequently repaired with driven 
plugs, having some level of interference fit. 
Pumping ports, threaded for a tapered pipe 
fitting, are often installed as a standard Yankee 
design feature for sealant injection into flange 
interfaces. When installed, both produce an 
area of increased stress, local to the hole's 
edge. In the case of driven plugs, this stress 
can be exaggerated by excessive interference 
fits and by closely-grouped or over-lapping 
plugs. Over-torque of threaded, tapered plugs 
can cause cracks to develop at the periphery 
of the hole. 



S5.3.2.5 THERMAL STRESS AND/OR 

MICRO-STRUCTURAL CHANGE 
FROM EXCESSIVE LOCAL 
HEATING AND COOLING 

Transient thermal stresses are usually the high- 
est encountered by a Yankee dryer. Temperature 
differential through and between parts can be 
of such magnitude as to exceed the strength 
of the material. When abnormal thermal loads 
occur, nondestructive examination is crucial 
to ensure the vessel's fitness-for-service. Micro- 
structural change and transient thermal stresses, 



sufficiently high to cause cracking in Yankee 
dryers, have resulted, or could result, from: 

a) bearing failure; 

b) rapid warm-up; 

c) excessive steam temperature; 

d) heat from fires; 

e) application of water sprays to fight fires and 
remove paper jams; 

f) continuous and excessive local cooling 
from water sprays; 

g) operating heating or cooling systems while 
the Yankee is stationary; e.g., high tem- 
perature air impingement hoods, infra-red 
heating devices, coating showers; 

h) welding and electrical arcs on cast-iron 
parts; and 

i) excessive local temperature due to im- 
proper thermal spray application. 

S5.3.2.6 JOINT INTERFACE CORROSION 

The products of corrosion occupy a larger 
volume than the base metal. The forces cre- 
ated by this expansion are sufficient to cause 
cracking in cast-iron flanges. Without remedia- 
tion, expansion will continue until failure oc- 
curs. Corrosion products form in the presence 
of moisture in the crevice created between 
flanges, wherever the clamping force is insuf- 
ficient to maintain contact between the mating 
surfaces. 



1 92 



NATIONAL BOARD INSPECTION CODE • PART Z 



INSPECTION 



S5.3.2.7 STRESS-CORROSION 

CRACKING OF STRUCTURAL 

BOLTS 

Stress-corrosion cracking (SCC) is the result of 
the combination of a corroding agent, mate- 
rial sensitivity, tensile stress, and temperature. 
At stress levels sufficiently high to induce SCC 
in the presence of a corrosive medium, attack 
proceeds along or through grain boundaries 
perpendicular to the direction of maximum 
tensile stress. Cracking can initiate with little 
or no evidence of general corrosion. 



S5.3.3 



CORROSION 



Corrosion culminates with a failure in compo- 
nent functionality by diminishing load-carrying 
capacity or by generating forces beyond the 
material's strength. In addition to SCC, corro- 
sion-jacking (head to shell joint), wear-corro- 
sion, and deterioration of washers described 
above, oxygen pitting, and general corrosion 
wastage need to be considered as potential 
failure causes. These latter two corrosion condi- 
tions are the result of inadequate boiler water 
treatment. Oxygen pitting has been encoun- 
tered, but rarely. 



S5.4 



INSPECTIONS 



a) Yankee dryers should be inspected on a 
routine-periodic basis. However, as a mini- 
mum, the Yankee dryer should be inspected 
internally and externally at least one time 
every two years. 

b) As appropriate, the following items should 
be included: 

1) head-to-shell joint; 

2) shell out-of-roundness; 

3) shell centerline thickness; 

4) tilt of head flange; 



5) integrity and security of internal parts; 

6) spigot fit of flanged joints (head-to- 
shell, head-to-journal); 

7) integrity of structural bolts and studs; 
and 

8) previously identified areas of deteriora- 
tion and damage. 

When a nonstandard load event occurs, 
or a material non-conformity is noted, an 
inspection should be performed to assess 
fitness for continued service. This inspec- 
tion may involve testing methods not typi- 
cally used in routine inspections and may 
also involve removal of material samples 
for destructive testing. 



S5.5 NONDESTRUCTIVE 

EXAMINATION 

a) Nondestructive examination (NDE) meth- 
ods shall be implemented by individuals 
qualified and experienced with the material 
to be tested using written NDE procedures. 
For Yankee dryers, cast-iron knowledge and 
experience are essential. 

b) Typical nondestructive examination meth- 
ods should be employed to determine 
indication length, depth, and orientation 
(sizing) of discontinuities in Yankee dry- 
ers. Magnetic particle, specifically the wet 
fluorescent method, and dye penetrant 
methods are applicable in the evaluation 
of surface-breaking indications. Ultrasonic 
testing is the standard method for evalua- 
tion of surface-breaking and embedded in- 
dications. Radiographic methods are useful 
in the evaluation of embedded indications. 
Acoustic Emission Testing can be used to 
locate and determine if a linear indication 
is active; i.e., propagating crack. Metallo- 
graphic analysis is useful in differentiating 
between original casting discontinuities 
and cracks. 



1 93 



NATIONAL BOARD INSPECTION CODE • PART 2 — INSPECTION 



c) When nondestructive testing produces an 
indication, the indication is subject to inter- 
pretation as false, relevant, or non-relevant. 
If it has been interpreted as relevant, the 
necessary subsequent evaluation will result 
in a decision to accept, repair, replace, 
monitor, or adjust the maximum allowable 
operating parameters. 



S5.6 



PRESSURE TESTING 



Water pressure testing in the field is not rec- 
ommended because of the large size of the 
Yankee dryers and the resulting combined 
weight of the Yankee dryer and the water 
used in testing. This combined weight can 
lead to support structure overload. Several 
failures of Yankee dryers have occurred 
during field pressure testing using water. If 
this test must occur, the following review 
is recommended: 



contact the Yankee dryer shell at each 
end near the head-to-shell joint. The 
manufacturer can provide information 
on saddle sizing and location so that 
the Yankee dryer is properly supported 
for the test. 

b) When pressure testing is desired to evaluate 
forms of deterioration, acoustic emission 
testing, with steam or air, is recommended. 
Typically, the test pressure used is the op- 
erating pressure. 



1 ) The testing area should be evaluated for 
maximum allowable loading, assum- 
ing the weight of the Yankee dryer, the 
weight of the water filling the Yankee 
dryer, and the weight of the support 
structure used to hold theYankee dryer 
during the test. 

2) The manufacturer should be contacted 
to provide information on building 
the Yankee dryer support structure for 
the water pressure test. Typically, the 
Yankee dryer is supported on saddles 
that contact the testing area and should 
be evaluated for maximum allowable 
loading, assuming the weight of the 
Yankee dryer, the weight of the water 
filling theYankee dryer, and the weight 
of the support structure used to hold the 
Yankee dryer during the test. 

3) The manufacturer should be contacted 
to provide information on building the 
Yankee dryer support structure for the 
water pressure test. Typically, the Yan- 
kee dryer is supported on saddles that 



1 94 



NATIONAL BOARD INSPECTION CODE • PART 2 



INSPECTION 



SUPPLEMENT 6 

CONTINUED SERVICE AND 
INSPECTION OF DOT 
TRANSPORT TANKS 



S6.3 



ADMINISTRATION 



S6.1 



SCOPE 



This supplement provides rules for contin- 
ued service inspections of transport tanks, 
i.e., cargo tanks, rail tanks, portable tanks, 
and Ton Tanks that transport dangerous 
goods as required in the Code of Federal 
Regulations, Title 49, Parts 100 through 
185, and the United Nations Recommen- 
dations for Transport of Dangerous Goods- 
Model Regulations. This supplement, where 
applicable, shall be used in conjunction 
with other applicable Parts of the National 
Board Inspection Code (NBIC) and Section 
XII, TransportTanks, of The ASM E Boiler and 
Pressure Vessel Code. 



S6.2 



TERMINOLOGY 



a) The terminology used in this supplement, 
in some cases may be in conflict with 
terms and definitions normally used in the 
repair and alteration of pressure-retaining 
items. Considering these differences, this 
supplement in the Definition Section has 
incorporated definitions and terms speci- 
fied in CFR 49, Parts 1 00 through 1 85. 

b) When conflicts are identified between this 
part and the regulations of the Competent 
Authority regarding the examination, in- 
spection, testing, repair, and maintenance 
for the continued qualification of transport 
tanks, the regulations of the Competent 
Authority take precedence. 

c) Rules for repairs and modifications of trans- 
port tanks are provided in Part 3, Repairs 
and Alterations, Supplement 6. 



b) 



The Competent Authority's requirements 
describe the frequency, scope, type of in- 
spection, (internal, external, or both), type 
of examination (nondestructive, spark test, 
etc.), and the documentation requirements 
for the inspection. 

For transport tanks under the Jurisdiction 
of the Department of Transportation, the 
Registered Inspector shall have a thorough 
knowledge of the Code of Federal Regula- 
tions, Title 49, Parts 1 00 through 1 85. 



S6.4 



INSPECTION 



This section will establish the appropriate meth- 
ods to be used for continued service inspec- 
tions. Inspections for repairs and modifications 
of transport tanks is located in Part 3, Repairs 
and Alterations, Supplement 6. 



S6.4.1 



SCOPE 



This section describes the duties, qualifications, 

and responsibilities of the Registered Inspector, 

ind the scope of inspection activities permitted. 



an 
a 



S6.4.2 GENERAL REQUIREMENTS FOR 

INSPECTORS 

a) The Inspector shall be a National Board rec- 
ognized Inspector, i.e., Authorized Inspec- 
tor (Al), Qualified Inspector (Ql), Certified 
Individual (CI), or a Registered Inspector 
(Rl). The Registered Inspector is a position 
established by CFR 49 Parts 100 through 
1 85 for Continued Service Inspections. This 
individuals duties and responsibilities are 
subject to DOT and not QAI-1 . 

b) For continued service inspections, the 
owner-user's Registered Inspector can be 



1 95 



NATIONAL BOARD INSPECTION CODE • PART Z 



INSPECTION 



used to perform inspections and testing 
in accordance with the Code of Federal 
Regulations, Title 49, Parts 100 through 
185, Transportation. 



S6.4.3 REGISTRATION OF INSPECTORS 

Each Registered Inspector performing duties 
and responsibilities for continued service in- 
spections or inspections for repairs and modi- 
fications as specified in this section and 49 CFR 
Part 180, is required to meet the qualification 
requirements of S6.4.4 , S6.4.6 and S6.4.7, as 
applicable to be registered with DOT. 



S6.4.4 QUALIFICATIONS OF 
INSPECTORS 

a) Registered Inspector (Rl) means a person 
registered with the US Department of 
Transportation (DOT) in accordance with 
Subpart F of Part 107 of 49 CFR who has 
the knowledge and ability to determine 
whether a cargo tank conforms to the ap- 
plicable DOT specification. A Registered 
Inspector may or may not be an employee 
of the approved facility. In addition, Regis- 
tered Inspector means a person who meets, 
at a minimum, any one of the following: 

1) Has an engineering degree and one 
year of work experience. 

2) Has an associate degree in engineering 
and two years of work experience. 

3) Has a high school diploma or CED and 
three years of work experience. 

4) Has at least three years experience in 
performing the duties of a Registered In- 
spector by September 1 , 1 991 , and was 
registered with the DOT by December 
31, 1995. 



S6.4.5 



CODES OF CONSTRUCTION 



a) The Registered Inspector is responsible 
to ensure that all repairs or modifications 
(including re-rating) are performed in ac- 
cordance with the original code of con- 
struction of the Transport Tank. 

b) For repairs or modifications, the original 
code of construction for DOT vessels shall 
be either ASME Section VIII Division I or 
Section XII. 



S6.4.6 INSPECTOR DUTIES FOR 

CONTINUED SERVICE 
INSPECTIONS 

a) Inspectors performing Continued Service 
Inspections required by the Code of Federal 
Regulations (CFR), Title 49, Part 1 80 shall be 
a Registered Inspector. The Inspector shall 
satisfy the following requirements: 

1) Has satisfied DOT requirements as a 
Registered Inspector. 

2) Has successfully completed the Na- 
tional Boards Web-based training 
program for Registered Inspectors and 
been issued a National Board certificate 
of completion. 

3) Has received authorization from DOT 
as a Registered Inspector. 

4) Has been registered by DOT for the 
Classification(s) of Transport Tanks to 
be inspected. 

b) Inspectors performing Continued Service 
Inspections meeting the requirements of 
S6.1 3 (Cargo Tanks), S6.14(PortableTanks), 
or S6.1 5 (Ton Tanks), and 49 CFR, Part 1 80 
shall perform all inspections and tests re- 
quired by this section and any additional 



1 9G 



NATIONAL BOARD INSPECTION CODE • PART 2 



INSPECTION 



requirements, as applicable in 49CFR Part 
180. The Inspections and Tests shall be 
documented as follows: 

1 ) All inspections and tests shall be con- 
ducted, as applicable, in accordance 
withS6.13, S6.14, andS6.15. 

2) All inspections and tests shall be 
documented in an Inspection Report 
as required by S6.5. 

3) All inspection and test reports shall be 
maintained by the Owner-User or Ship- 
per of the transport tank in accordance 
with S6.5. 



b) 



the following requirements for Periodic 
Inspection andTest Frequencies in S6.1 3 
are properly satisfied as specified by: 

a. Periodic Inspection and Test frequen- 
cies: Table S6.13 

b. Pressure Test Requirements for Cargo 
Tank by specification: Table S6.1 3.6 

Additional criteria for material thickness 
requirements for a cargo tank specification 
are listed, as applicable for material type 
(ferrous and non ferrous) in various tables 
in S6.13. 



4) All inspection and test reports shall be 
available for review by an authorized 
representative of the Department of 
Transportation. 

The requirements for inspections are pro- 
vided for each classification of transport 
tanks as specified in S6.4.6.1, cargo tanks, 
S6.4.6.2, portable tanks and S6.4.6.3, ton 
tanks. 



S6.4.6.1 INSPECTOR DUTIES FOR 

CONTINUED SERVICE 
INSPECTION OF CARGO TANKS 

a) Cargo tanks constructed in accordance 
with a DOT Specification that are required 
to be tested or inspected can not be used 
for transportation until the required test 
or inspection has been successfully com- 
pleted. 

1) The Registered Inspector shall inspect 
cargo tanks in accordance with S6.1 3, 
and in conjunction with the require- 
ments of 49CFR Partsl 80.401 through 

1 80.41 7. 



S6.4.6.2 INSPECTOR DUTIES FOR 
CONTINUED SERVICE 
INSPECTION OF PORTABLE 
TANKS 

a) Portable Tanks constructed in accordance 
with DOT, United Nations (UN), or Inter 
Modal (IM) specifications that are required 
to be tested or inspected cannot be used 
for transportation until the required test or 
inspections have been successfully com- 
pleted. 

b) The Registered Inspector shall inspect 
portable tanks in accordance with S6.14, 
in conjunction with the requirements of 
49CFR, Parts 180.601 to 180.605. 

c) The Registered Inspector in the performance 
of his or her duties shall ensure that the fol- 
lowing requirements for Inspection Intervals 
and Pressure Test Requirements in S6.14are 
properly satisfied as specified by: 

1) Inspection Intervals: Table S6. 14 

2) Pressure Testing Requirements: Table 
S6.14.6 



The Registered Inspector in the perfor- 
mance of their duties shall ensure that 



1 97 



NATIONAL BOARD INSPECTION CODE • PART 2 — INSPECTION 



S6.4.6.3 INSPECTOR DUTIES FOR 

CONTINUED SERVICE 
INSPECTIONS OF TON TANKS 

a) Ton Tanks constructed in accordance with 
DOT 106A or DOT 110A requirements 
that are required to be tested and inspected 
can not be used for transportation until 
the required test and inspection has been 
made. 

b) The Registered Inspector shall inspect ton 
tanks in accordance with S6.15, in con- 
junction with the requirements of 49CFR, 
Part 180.519. 

c) The Registered Inspector in the performance 
of his or her duties shall ensure that the re- 
quirements forTon Tank Periodic Inspection 
and Test Frequencies in Table S6.15.3 are 
properly satisfied. 

d) Additional criteria for material thickness, 
safety valve, and acceptable material with 
acceptable tensile strength and elongation 
requirements for ton tanks are listed in the 
following tables of S6.1 5: 

1) Thickness of Plate and Safety Valve 
Requirements: Table S6. 15.1 -a 

2) Acceptable Materials with Acceptable 
Tensile Strength and Elongation Re- 
quirements: Table S6.1 5.1 -b 



S6.4.7 CONTINUED SERVICE, 
INSPECTION FOR DOT 

TRANSPORT TANKS SCOPE 

This supplement details frequencies of testing 
requirements, type of tests required, acceptance 
criteria, and inspection reports of transport 
tanks. 



S6.4.7.1 ADMINISTRATION 

The Competent Authority's requirements de- 
scribe the frequency, scope, type of inspec- 



tion, and documentation requirements for the 
inspection and are noted in the US Code of 
Federal Regulations, Title 49 CFR, Parts 100 
through 185. 



S6.4.7.2 INSPECTION AND TEST 

REQUIRED FREQUENCIES 

Inspection and frequencies for periodic test- 
ing of cargo tanks are found in S6.1 3; portable 
tanks S6.14; and ton tanks S6.15. 



S6.4.7.3 EXTERNAL VISUAL AND 
PRESSURE TESTS 

External visual inspection tests shall be per- 
formed in accordance with S6.13.1 for cargo 
tanks; S6.14.5 for portable tanks; and S6.15.2 
for ton tanks. The pressure tests for cargo tanks 
shall be as specified in S6.13.6; S6.14.6 for 
portable tanks; and S6.1 5.3 for ton tanks. 



S6.4.7.4 LEAK TIGHTNESS TESTING OF 
TRANSPORT TANKS 



S6.4.7.4.1 CARGO TANKS 

a) Each cargo tank must be tested for leaks 
in accordance with Table S6.13, Periodic 
Inspections and Jest, and per the require- 
ments in S6.13.9. The minimum leakage 
test pressure of 80% of MAWP may be 
accepted by provisions of the Competent 
Authority [see 49CFR1 80.407(h)]. 

b) All external and accessible portions of 
piping up to the first closure when offered 
for transportation shall be tested for leak 
tightness. 

1) All closure fittings must be in place 
during the leak tightness test. 

2) The leak tightness test pressure must be 
maintained for at least 5 minutes. 



1 98 



NATIONAL BOARD INSPECTION CODE • PART Z — INSPECTION 



3) All sources of leakage must be properly 
repaired. 

4) A cargo tank that fails to retain leakage 
test pressure may not be returned to 
service as a specification cargo tank. 



should coincide with the leak test for piping as 
specified in S6.4.7.4.T and shall include: 

a) All valves under pressure shall be leak 
tested at the pressure specified, for leak- 
age through the valve, and externally (e.g., 
valve bonnet.) 



S6.4.7.4.2 PORTABLE TANKS 

Each portable tank piping must be tested for 
leaks in accordance with the inspection inter- 
vals in Table S6.14 and per the procedures in 
S6.14.6. 

a) The minimum leakage test pressure is as 
specified in Table S6.14.6 

b) All closure fittings must be in place during 
the leak tightness test. 

c) The test pressure must be maintained for at 
least 5 minutes. 

d) All sources of leakage must be properly 
repaired. 

e) A portable tank that fails to retain leakage 
test pressure may not be returned to service 
as a specification portable tank. 



S6.4.7.4.3 TON TANKS 



b) During the inspection a suitable method 
must be used for detecting the existence 
of leaks. This method must consist either of 
coating the entire surface of all joints under 
pressure with a solution of soap and water, 
or using other equally sensitive methods. 

c) All emergency devices and valves includ- 
ing self-closing stop valves, excess flow 
valves and remote closure devices must 
be free from corrosion, distortion, erosion, 
and external damage that will prevent safe 
operation. Remote closure devices and self 
closing stop valves must be functioned to 
demonstrate proper operation. 



S6.4.7.4.4.2 PORTABLE TANKS 

Portable tank valves shall be periodically visu- 
ally inspected in accordance with the appli- 
cable provisions of S6.14.3 and leak tested at 
time intervals specified in S6.14. Leak tightness 
testing requirements are as specified in Table 
S6.14.6 and shall include: 



Each ton tank shall be tested at intervals speci- 
fied in Table S6. 15.3, by procedure at pressures 
specified for the classification of the tank. 



S6.4.7.4.4 LEAK TIGHTNESS TESTING OF 
VALVES 



S6.4.7.4.4.1 CARGO TANKS 



a) Piping, valves, and gaskets must be free 
from corroded areas, defects, and other 
conditions, including leakage, that might 
render the portable tank unsafe for filling, 
discharge, or transportation. 

b) All emergency valves shall be free from 
corrosion, distortion, and any damage or 
defect that could prevent their normal op- 
eration. 



Cargo tank valves shall be periodically visually 
inspected in accordance with the applicable 
provisions in S6. 13.2(e) and leak tested at 
time intervals specified in Table S6.1 3. This test 



c) Remote closure devices and self-closing 
stop valves must be functioned to demon- 
strate proper operation. 



1 99 



NATIONAL BOARD INSPECTION CODE • PART 2 — INSPECTION 



d) For testing of interna] self-closing stop valves 
see Appendix A and B of 49CFR1 80. 

e) The intermediate periodic inspection and 
test shall include an internal and external 
inspection, unless exempted, and an ex- 
ternal inspection of the portable tank and 
fittings, leakage test, and test for satisfactory 
operation of all service equipment. 



S6.4.7.4.4.3 TON TANKS 

Ton tanks valves shall be periodically visually 
inspected in accordance with the applicable 
provisions of S6.15.2 and leak tested in ac- 
cordance with the provisions of S6.15.3 and 
S6. 15.3.1. This test should coincide with the 
tank retest intervals as stipulated in Table 
S6.15.3 



S6.4.7.5 LEAK TIGHTNESS TESTING OF 
SAFETY RELIEF DEVICES 



S6.4.7.5.1 CARGO TANKS 

a) All re-closing pressure relief devices for 
cargo tanks shall be visually inspected 
per S6. 13.2(e) and pressure tested for leak 
tightness as stipulated in S6.1 3.6(b) at fre- 
quencies specified in Table S6.1 3. 

Note: when performing this test, all re- 
closing pressure relief valves, including 
emergency relief vents, and normal vents 
shall be removed for inspection and tested 
as follows: 

b) Leakage test for any venting device re- 
quired for the interval specified in Table 
S6.13 must include testing the device in 
place, except that any venting device set to 
discharge at less than the leakage pressure 
must be removed or rendered inoperative 
during the test. 



Non re-closing relief device discs should 
be evaluated for replacement at the time 
of the pressure test intervals. 



S6.4.7.5.2 PORTABLE TANKS 

Portable tanks subject to a five-year periodic 
inspection and leak tightness test, except for 
DOT Specification 56 and 57 Portable Tanks 
shall include: 

a) All re-closing pressure relief devices must 
be removed from the tank and tested 
separately unless they can be tested while 
installed on the portable tank. 

b) If a leakage test is specified being less than 
the MAWP, the re-closing pressure relief 
valves can be tested in place. 

c) Visual inspection shall include all emer- 
gency devices to ensure that they are free 
from corrosion, distortion, and any damage 
or defects that could prevent the devices 
from operating as designed. 

d) For Specification 57 Portable Tanks, during 
the air test, the pressure relief device may be 
removed or left in place. If the relief device 
is left in place during the test, the device's 
discharge opening shall be plugged. (See 
Special Requirements for testing of pressure 
relief devices for Specifications 51 and 56 
Portable Tanks in S6.1 4.6.2.) 

e) For Specification 60 PortableTanks, re-clos- 
ing pressure relief devices may be removed 
from the tank and tested separately unless 
they can be tested while installed in the 
portable tank. 

f) If portable tanks are fitted with non-reclos- 
ing relieving devices, consideration for 
replacing the discs for these devices should 
be evaluated at the time of the leak tightness 
test interval. 



2DD 



NATIONAL BOARD INSPECTION CDDE • PART 2 



INSPECTION 



S6.4.7.5.3 TON TANKS 

Each ton tank designed to be removed from 
tank cars for filling and emptying shall have 
their safety relief devices, if fitted, tested and 
subjected to a periodic inspection and test at 
frequencies established in Table S6.1 5.3. 

a) All pressure relief devices shall be retested 
by air or gas for the start-to-discharge and 
vapor tightness requirements. 

b) For ton tanks fitted with rupture discs and 
fusible plugs, the inspection of these de- 
vices and disposition must be as described 
in S6.15.3.3. 



S6.4.7.6 TESTING OF MISCELLANEOUS 
PRESSURE PARTS 



S6.4.7.6.1 CARGO TANKS 

Cargo tanks provided with manholes (or hand- 
holes) shall be inspected in accordance with 
S6.13.2 and all major structural attachments 
as defined in CFR1 80.407(d)(2)(viii), including 
the upper coupler (fifth wheel) assembly and 
ring stiffeners shall be inspected in accordance 
with S6.1 3.3. Other miscellaneous items shall 
comply with the following: 

a) Cargo tanks equipped with linings that 
protect the cargo tank from the commod- 
ity being transported, shall be inspected, 
unless exempted, in accordance with the 
provisions of S6.13.5. 

b) For cargo tanks equipped with a heating 
system, the heating system shall be pressure 
tested as required by S6. 13.6.4. 

c) Delivery hoses for MC330 and MC331 
cargo tanks shall be leak tightness tested. 
Any conditions as noted in S6.1 3.9, which 
exist for the delivery hose, shall be unac- 
ceptable and prevent its continued use. 



d) New or replaced delivery hose assem- 
blies shall meet all of the requirements of 
S6. 13.10. In addition to this requirement, 
for commodities transported in MC330 and 
MC331, the delivery hose assemblies may 
be installed or carried on the cargo tank. 
The operator is required to perform inspec- 
tions as required in 49CFR1 80.41 6. 



S6.4.7.6.2 PORTABLE TANK 

For portable tanks, the periodic visual inspec- 
tion shall include: 

a) The operation of tightening devices for 
manhole and handhole covers, or the gas- 
kets are operative and there is no leakage 
at the manhole or handhole cover or gasket 
at leakage pressure. 

b) The framework structural supports and the 
lifting device located on the portable tank 
shall be in satisfactory condition. 



S6.4.7.6.3 TON TANKS 

Visual inspection of ton tanks shall include dam- 
aged chimes or protective rings if so fitted. 



S6.4.7.7 ACCEPTANCE CRITERIA 

All defects or deficiencies discovered during the 
inspection process of a transport tank shall be 
documented in the Inspection Report and dis- 
cussed with the owner or user of the transport 
tank at the time of the inspection. Defects or 
deficiencies shall be corrected using appropri- 
ate methods, and tested prior to returning the 
transport tank to service. (See S6.1 0.) 



ZD 1 



NATIONAL BOARD INSPECTION CODE • PART Z — INSPECTION 



S6.4.7.8 INSPECTION REPORT 



S6.5.2 



STAMPING 



S6.4.7.8.1 CARGO TANKS 

Cargo tank Inspection Reports, as a minimum, 
shall include the information specified in 
S6.13.6.7 and S6.13.8 (as applicable) and 
49CFR180.417. 



S6.4.7.8.2 PORTABLE TANKS 

Portable tank Inspection Reports shall satisfy the 
requirements of S6. 14.9 in addition to those of 
49CFR Part 180.605. 



S6.4.7.8.3 TON TANKS 

Ton tank Inspection Reports shall satisfy the 
requirements of S6.1 5.3.6 in addition to those 
of 49CFR Part 180.51 9. 



S6.5 STAMPING AND RECORD 

REQUIREMENTS FOR DOT 
TRANSPORT TANKS IN 

CONTINUED SERVICE 

This section provides for preparation, distribu- 
tion and maintenance of inspection records and 
stamping requirements for Continued Service 
Inspections of Transport Tanks, i.e., cargo tanks, 
portable tanks, and ton tanks. 



S6.5.1 



GENERAL 



To ensure that transport tanks can maintain their 
authorization to transport hazardous materi- 
als by the mode of transport permitted by the 
Competent Authority (DOT), the specification 
transport tank's owner or user shall satisfy, 
as applicable, that the records and stamping 
requirements of this supplement and Code of 
Federal Regulations, Title 49, Part 1 80 (49 CFR 
1 80), have been satisfied. 



a) Transport tanks represented as manufac- 
tured to a DOT specification or a United 
Nation's (UN) standard shall be marked 
on a non-removable component of the 
transport tank with specification markings 
conforming to the applicable specification. 
The specification marking is required to be 
located in an unobstructed area with letters 
and numerals identifying the standard or 
specification. Unless otherwise specified by 
Part 1 78.3 of the Code of Federal Regula- 
tions, the markings must identify the name 
and address or symbol of the transport 
tank manufacturer or, where specifically 
authorized, the symbol of the approval 
agency certifying compliance with a UN 
standard. 

b) Symbols required by the Department of 
Transportation (DOT) must be with the ap- 
proval of the DOT Associate Administrator. 
Duplicative symbols are not authorized. 
Stamping and symbol requirements for 
transport tanks that are under different rules 
than CFR 49, Parts 100 through 185 shall 
comply with the applicable Competent 
Authorities rules and regulations. 

c) The detailed markings, i.e., stamped, em- 
bossed, burned, printed, etc., size of the 
markings, capacities, etc., are specified in 
Part 1 78.3 of the Code of Federal Regula- 
tions, Title 49, as follows: 

1 ) ASME-Stamped Transport Tanks 

a. Transport tanks stamped with the 
ASME Section XII Code Symbol 
shall satisfy the applicable require- 
ments of that Code. Transport tanks 
manufactured prior to the adoption 
of ASME Section XII by the Compe- 
tent Authority were manufactured 
in accordance with ASME Section 
VIII, Div. 1. Stamping with the 
ASME Section VIM, Div. 1 "U" Code 



2D2 



NATIDNAL BOARD INSPECTION CODE • PART 2 



INSPECTION 



Symbol Stamp is dependant on 
pressure and/or media limitations. 

b. When the stamping on a transport 
tank becomes indistinct or the 
nameplate is lost or illegible, but 
traceability to the original transport 
tank is still possible. To satisfy this 
requirement, as a minimum, origi- 
nal source data from the manufac- 
turer of the vessel or records in pos- 
session of the tank owner should 
be used to establish traceablity to 
the stamping with the concurrence 
of the Inspector, and approval of 
the Competent Authority, and if re- 
quired the Jurisdiction. The Inspec- 
tor shall instruct the owner or user 
to have the stamped data replaced. 
All re-stamping shall be done in 
accordance with the original code 
of construction (ASME Section XII, 
or ASME Section VIII, Div. 1 , as ap- 
plicable). Request for permission to 
re-stamp or replace the nameplate 
shall be made to the Competent 
Authority and, if required, the Juris- 
diction. Application must be made 
on the Replacement of Stamped 
Data Form, NB-136 (See 5.5.2). 
Proof of the stamping and other 
such data, as is available, shall be 
furnished with the request. When 
traceability cannot be established, 
the Competent Authority shall be 
contacted. 

2) Re-stamping or replacement of name- 
plates 

Re-stamping or replacement of the 
nameplate as authorized by the Com- 
petent Authority shall only be done 
in the presence of the Inspector, i.e., 
Al, Ql, CI, or National Board Com- 
missioned Inspector, as required by 
ASME Section XII and the applicable 
Modal Appendix, or as required by 
the Competent Authority. For transport 



tanks manufactured to ASME Section 
VIII, Div. 1, re-stamping or replacement 
shall only by done in the presence of 
an Authorized Inspector or a National 
Board Commissioned Inspector. 



S6.5.3 OWNER OR USER REQUIRED 

RECORDS FOR CARGO TANKS 

a) Each Owner or User of a DOT Specifica- 
tion cargo tank shall retain the appropriate 
ASME Manufacturer's Data Report, Form 
T-1, for Section XII Transport Tanks or Form 
U-1A for Section VIII, Division 1 Pressure 
Vessels, and related papers certifying that 
the DOT Specification cargo tank identified 
in the documents was manufactured and 
tested in accordance with the applicable 
tank specification. 

1) In addition to the appropriate ASME 
Manufacturer's Data Report, the re- 
quired documents shall include any 
certification of emergency discharge 
control systems required by 49 CFR 
173.315(h) or 49 CFR 180.405(m). 

a. The Certificate of Compliance is- 
sued by the cargo tank motor ve- 
hicle manufacturer (CTMVM) and 
all preceding certificates issued by 
preceding manufacturers signed 
and dated by a Registered Inspec- 
tor or Company Official or Design 
Certifying Engineer as required by 
49 CFR 178.337-1 8(a)(1) or (a)(2) 
as appropriate. The certificate must 
contain a statement indicating 
whether or not the cargo tank was 
postweld heat treated for anhydrous 
ammonia service as specified in 49 
CFR 1 78.337-1 (f); 

b. Cargo tank fabrication drawings; 

c. Piping drawing that identifies the 
location, make, model, and size of 



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NATIONAL BDARD INSPECTION CODE • PART 2 



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each valve and the arrangement of 
all piping associated with the cargo 
tank motor vehicle; 

d. Assembly drawing; 

e. Pressure test report for the piping, 
valves and fittings; 

f. Hose certification; and 

g. Certification of emergency dis- 
charge control systems. 

2) The documents required by 49 CFR 
shall be retained throughout ownership 
of the cargo tank and for one year after 
relinquishing ownership. 

3) In the event of a change in ownership, 
the prior owner shall retain non-fading 
photocopies of these documents for 
one year. 

4) Users of a cargo tank that are not the 
Owner shall retain a copy of the vehicle 
certification report as long as the cargo 
tank motor vehicle is used by the User 
and for one year thereafter. 

5) The required documents specified in 
this Section shall be maintained at the 
Owner or Users principal place of busi- 
ness, or at a location where the cargo 
tank is housed or maintained. 

6) Items (4) and (5) do not apply if the User 
leases the cargo tank for less than 30 
days. 

b) For DOT Specification cargo tanks that 
were manufactured prior to September 1, 
1995, that were not constructed to ASME 
Section VIII, Division 1 (Non Code Pressure 
Vessels), but wishes to certify the cargo tank 
to a DOT Specification Cargo Tank, the fol- 
lowing shall be complied with: 

1 ) The Owner shall perform the appropri- 
ate tests and inspections as required 



by 49 CFR Part 178 under the direct 
supervision of a Registered Inspector to 
determine if the cargo tank conforms to 
the applicable specification. 

2) Both the Owner and the Registered 
Inspector shall certify that the cargo 
tank fully conforms to the applicable 
specification. 

3) The Owner shall maintain the certifica- 
tion as specified in this section. 

For ASME -stamped cargo tanks, the Owner 
must have the manufacturer's certification 
and the appropriate ASME Manufacturer's 
Data Report on file. 

1) If the Owner does not have the manu- 
facturer's certification and the appropri- 
ate ASME Manufacturer's Data Report, 
the following shall be satisfied: 

a. If the pressure vessel of the cargo 
tank is registered with the National 
Board of Boiler and Pressure Ves- 
sel Inspectors (National Board), 
he shall obtain a copy of the 
Manufacturer's Data Report from 
the National Board. 

b. If the pressure vessel of the cargo 
tank is not registered with the 
National Board, he shall copy the 
cargo tank's identification and 
ASME Code nameplate information 
and retain this information in his 
files. 

2) If the nameplate information is copied 
as identified in (c)(1 )b., the Owner and 
the Registered Inspector shall certify 
that the pressure vessel of the cargo 
tank fully conforms to the DOT speci- 
fication. 

3) The Owner shall retain all certification 
documents in accordance with reten- 
tion periods specified in this supple- 
ment. 



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S6.5.3.1 REPORTING REQUIREMENTS BY 
THE OWNER OR USER OF TESTS 

AND INSPECTIONS OF DOT 
SPECIFICATION CARGO TANKS 

The Owner or User that performs the required 
Test and the Registered Inspector that performs 
the inspection as specified at frequencies es- 
tablished in Table S6. 13 shall prepare a written 
report in English that satisfies the requirements 
ofS6.13. Each test and inspection facility that 
fails a cargo tank based on a test or inspection 
report, shall notify the owner, register the report 
with the National Board, and provide a copy 
of the test report indicating the failure to the 
competent authority. 



S6.5.3.2 DOT MARKING REQUIREMENTS 
FOR TEST AND INSPECTIONS 
OF DOT SPECIFICATION 
CARGO TANKS 

Each cargo tank that has successfully completed 
the test and inspection contained in S6.13 shall 
be durably and legibly marked, in English. The 
markings shall comply with the following: 

a) Date (month and year) of the type of test 
or inspection performed, subject to the fol- 
lowing: 

1) date shall be readily identifiable with 
the applicable test or inspection; 

2) markings shall be 32mm (1.25 in.) 
high, near the specification plate or 
anywhere on the front head of the cargo 
tank. 

b) The type of test or inspection may be ab- 
breviated as follows: 

1 ) "V" for external visual inspection; 

2) "I" for internal visual inspection; 

3) "?" for pressure test; 

4) "L" for lining inspection; 



5) "T" for thickness inspection; 

6) "K" for leakage test for a cargo tank 
tested to the requirements of S6.13.9, 
except for cargo tanks subject to the 
requirements of S6.1 3.9 (d)(1 0); and 

7) "K-EPA27" for a cargo tank tested to the 
requirements of S6. 13. 9(d)(10)that was 
manufactured after October 1 , 2004. 

c) For a cargo tank motor vehicle composed 
of multiple cargo tanks constructed to the 
same specification, which are tested and 
inspected at the same time, one set of test 
and inspection markings may be used to 
satisfy the requirements of S6.5.3.2. 

d) For a cargo tank motor vehicle composed 
of multiple cargo tanks constructed to dif- 
ferent specifications, which are tested and 
inspected at different intervals, the test and 
inspection markings shall appear in the 
order of the cargo tank's corresponding 
location, from front to rear. 



S6.5.4 OWNER OR USER REQUIRED 

RECORDS FOR PORTABLE 

TANKS 

a) The Owner of each portable tank or his 
authorized agent shall retain a written re- 
cord of the date and results of all required 
inspections and tests, including the ASME 
Manufacturer's Data Report. 

b) The written record, if applicable, shall in- 
dicate the name and address of the person 
that performed the inspection or test. The 
inspection and test shall comply with the 
requirements of the portable tank's speci- 
fication, as provided in 49 CFR, Part 1 78. 

c) The Owner shall maintain a copy of the 
ASME Manufacturer's Data Report. He shall 
also maintain a certificate(s) that is signed 
by the manufacturer of the portable tank, 
and by the authorized design approval 



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NATIONAL BOARD INSPECTION CODE • PART Z 



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agency, as applicable indicating compli- 
ance with the applicable portable tank 
specification. 

d) The signed certificate, including the ASME 
Manufacturer's Data Report shall be main- 
tained by the Owner or his authorized 
agent during the time that the portable tank 
is used for service. DOT Specifications 56 
and 57 portable tanks are exempt from this 
requirement. 



c) When required, the date (month and year) 
of the last visual inspection; 

d) Markings shall be placed on or near the 
metal identification plate; and 

e) Markings shall be 3mm (0.118 in) high 
when on the metal identification plate and 
1 2 mm (0.47 in.) high when on the portable 
tank. 



S6.5.4.1 REPORTING OF PERIODIC AND 
INTERMEDIATE PERIODIC 
INSPECTION AND TESTS OF 
DOT SPECIFICATION PORTABLE 

TANKS 



S6.5.4.3 DOT MARKING REQUIREMENTS 
FOR PERIODIC AND 
INTERMEDIATE INSPECTION 
AND TESTS OF DOT 
SPECIFICATION 51, 56, 57, OR 
60 PORTABLE TANKS 



a) The user of portable tanks shall satisfy the 
requirements for Periodic and Intermediate 
Periodic Inspection and Tests of portable 
tanks as specified in Table S6.14 of this 
Supplement and shall maintain the results 
of these tests as required in S6.5.4. 

b) The methods and procedures to be used in 
the performance of the required Periodic 
and Intermediate Inspections and Tests are 
specified in S6.14. 



S6.5.4.2 MARKING REQUIREMENTS FOR 
PERIODIC AND INTERMEDIATE 
INSPECTION AND TEST FOR IM 
OR UN PORTABLE TANKS 

Each IM or UN portable tank that has success- 
fully completed the required Periodic or Inter- 
mediate Inspection and Test shall be durably 
and legibly marked, in English. The markings 
shall comply with the following: 

a) Date (month and year) of the last pressure 
test- 



Each DOT Specification 51, 56, 57, or 60 por- 
table tank that has successfully completed the 
required Periodic or Intermediate Inspection 
and Test shall be durably and legibly marked, 
in English. The markings shall comply with the 
following: 

a) Date (month and year) of the most recent 
test; 

b) Markings shall be placed on or near the 
metal certification plate; 

c) Markings shall be accordance with 49 CFR, 
Part 1 78.3; 

d) Letters and numerals shall not be less than 
3mm (0.118 in.) high, when on a metal 
certification plate and 12 mm (0.47 in) on 
the portable tank, except that a portable 
tank manufactured under a previously au- 
thorized specification may continue to be 
marked with smaller markings if originally 
authorized under that specification (for 
example, DOT specification 57portable 
tanks). 



b) Identification markings of the approval 
agency witnessing the test; 



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S6.5.5 OWNER OR USER REQUIRED 

REPORTS FOR DOT 

SPECIFICATION 106AAND 
DOT 110A TON TANKS 

a) The Owner or User of a DOT Specifica- 
tion ton tank shall retain the certificate of 
construction(AAR-Form 4-2) and related 
papers certifying that the manufacturer 
of the specification tank identified in the 
documents is in accordance with the ap- 
plicable specification. 

b) The Owner or User shall retain the docu- 
ments throughout the period of ownership 
of the specification ton tank and for one 
year thereafter. 

c) Upon a change in ownership of the specifi- 
cation ton tank, the owner shall satisfy the 
requirements of Section 1.3.15 of the ARR 
Specification. 



S6.5.5.1 REPORTING OF INSPECTION 
AND TESTS FOR DOT 
SPECIFICATION 106AAND 
DOT 110A TON TANKS 

a) The Owner or User shall inspect and test 
ton tanks at frequencies specified in Table 
S6.15.3 and shall perform the inspections 
and tests in accordance with S6.1 5.3. 

b) The Owner or User is required to develop 
a written record of the results of the pres- 
sure test and visual inspection and shall 
record the information on a suitable data 
sheet. Completed copies of these reports 
shall be retained by the owner and by the 
person performing the pressure test and 
visual inspection, as long as the ton tank 
is in service. 

c) The required information to be recorded 
and checked on these data sheets are: 

1 ) Date of test and inspection; 

2) DOT Specification Number; 



3) Ton tank identification (registered sym- 
bol and serial number); 

4) Date of manufacturer and ownership 
symbol; 

5) Type of protective coating (painted, 
etc.), and statement as to need for re- 
finishing or recoating; 

6) Conditions checked, i.e., leakage, cor- 
rosion, gouges, dents or digs, broken or 
damaged chime or protective ring, fire, 
fire damage, internal condition; 

7) Test pressure; 

8) Results of tests; 

9) Disposition of ton tank (returned to 
service, returned to manufacturer for 
repair, or scraped); and 

1 0) Identification of person conducting the 
retest or inspection. 

d) If a Retest Inspection is required, the Owner 
or User shall prepare a written report in 
accordance with S6.1 5.3.6 of this supple- 
ment. 



S6.5.5.2 DOT MARKING REQUIREMENTS 
FOR TEST AND INSPECTION OF 
DOT SPECIFICATION 106A AND 

110A TON TANKS 

a) When a ton tank passes the required inspec- 
tion and test with acceptable results, the 
tank car facility shall mark the following 
information on the ton tank: 

1 ) Date of the inspection and test; 

2) Due date of the next inspection and 
test; 

3) The markings on the ton tank shall be 
in accordance with Appendix C of the 
ARR Specifications for Tank Cars. 



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NATIONAL BOARD INSPECTION CODE • PART 2 — INSPECTION 



b) When a tank car facility performs multiple 
inspections and tests at the same time, one 
date may be used to satisfy the requirements 
of S6.5.5.2. Additionally, one date may be 
shown when multiple inspections and tests 
have the same due date. 



S6.6 CORROSION AND FAILURE 

MECHANISMS IN TRANSPORT 
TANKS 



S6.6.3 INTERNAL AND/OR 

EXTERNAL CORROSION 

Internal and/or external wastage from corrosion 
is probably one of the most common causes of 
deterioration in transport tanks while in opera- 
tion. All metals and alloys are susceptible to 
corrosion. Corrosion is deterioration that occurs 
when a metal reacts with its environment. Cor- 
rosion can be classified based on three factors. 
These factors are: 



An effective inspection and test program re- 
quires an understanding of the applicable po- 
tential failure mechanisms and the applicable 
inspection and test methods to assure the con- 
tinued structural integrity of a transport tank. 



S6.6.1 



SCOPE 



This section provides an overview of the causes 
of deterioration, and failure mechanisms in 
transport tanks. As provided in this overview, 
some forms of deterioration, and failure mecha- 
nisms may include stress corrosion cracking, 
fatigue, and temperature gradients (brittle 
fracture behavior) applicable to transport tanks 
during their normal operation. 



S6.6.2 



GENERAL 



a) This supplement includes a general dis- 
cussion of mechanisms and effective in- 
spection and test methods. Additionally, 
some specific guidance is given on how 
to evaluate the transport tanks for repairs, 
modifications, and continued service re- 
quirements. 

b) There are a variety of inservice conditions 
that may cause deterioration of the materi- 
als used in the construction of transport 
tanks. These inservice conditions should 
be taken into consideration during any 
repair activity. Prior to any repair activity, 
it is important to identify the cause of the 
deterioration, and to prevent its re-occur- 
rence. 



a) Nature 

1 ) Wet — liquid or moisture present in the 
transport tank 

2) Dry — high temperatures that may be 
present in the transport tank 

b) Mechanism — electrochemical or direct 
chemical reactions 

c) Appearance — either uniform or local- 
ized 



S6.6.3.1 TYPES OF CORROSION 

To implement the proper corrective actions will 
depend on which factors caused the problems, 
making it important to diagnose the reason for 
failure. Early detection of corrosion problems 
are important to prevent failures and can be 
achieved by performing regular inspections and 
encouraging employees to be observant and 
communicate their observations. The following 
types of corrosion mechanisms are commonly 
found in transport tanks: 

a) Pitting Corrosion 

Pitting corrosion is the formation of holes 
in an otherwise relatively un-attacked sur- 
face. Some of the characteristics of pitting 
corrosion are: 

1) Usually a slow process causing iso- 
lated, scattered pitting over a small 
area that does not substantial ly weaken 



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NATIONAL BOARD INSPECTION CODE • PART Z 



INSPECTION 



the transport tank. It could, however, 
eventually cause leakage. 

2) In some cases, local corrosion pits can 
be caused by microbiological activity, 
commonly known as MIC (microbio- 
logical ly influenced corrosion) attack. 

3) Generally, the area of the steel sur- 
rounding a corrosion pit from MIC will 
exhibit discoloration or a ring as evi- 
dence of a thriving bacteria colony. 

b) Line Corrosion 

This is a condition where pits are con- 
nected, or nearly connected to each other 
in a narrow band or line. Line corrosion 
frequently occurs in the interior surfaces 
of a transport at the following locations: 

1) the liquid-vapor interface in the trans- 
port tank, or 

2) the bottom of the transport tank. 

c) General Corrosion 

This is corrosion that covers a considerable 
area of the vessel surface of the transport 
tank. When this condition occurs, the 
owner-user of the transport tanks has to 
consider if this condition has compromised 
the continued safe operation of the trans- 
port tank. The following should be used in 
making this determination: 

1 ) inspect the affected area or areas to en- 
sure that the required minimum thick- 
ness of the vessel is within acceptable 
limits, and 

2) if the affected area or areas minimum 
thickness is below tolerance, depend- 
ing on the degree of deterioration, re- 
store the area or areas to the required 
thickness by using the weld build-up 
method or a flush patch. 



d) Grooving Corrosion 

This type of corrosion is a form of metal de- 
terioration caused by localized corrosion, 
and may be accelerated by stress concen- 
tration. Grooving is generally noticed: 

1 ) adjacent to welded surfaces, and 

2) on flange mating surfaces. 

e) Exfoliation and Selective Leaching 

1 ) Exfoliation is a subsurface corrosion that 
begins on a clean surface, but spreads 
below the surface of the metal. This 
type of corrosion differs from pitting in 
that the damage to the metal exhibits a 
laminated appearance, recognized by a 
flaky and sometimes blistered surface. 

2) Selective leaching results in the removal 
of one of the elements in an alloy mate- 
rial. This corrosion mechanism is detri- 
mental because it yields a porous metal 
with poor mechanical properties. 

f) Galvanic Corrosion 

1) Occurs when two dissimilar metals 
come in contact with each other in the 
presence of an electrolyte (i.e., film of 
water containing dissolved oxygen, 
nitrogen, and carbon dioxide) constitut- 
ing an electrolytic cell. The difference 
in galvanic potential between the two 
dissimilar materials creates a local 
electrical cell that may cause rapid 
corrosion of the less noble metal. This 
corrosion mechanism becomes more 
active when there are large differences 
between the electrode potentials of the 
two metals. 

2) Galvanic corrosion may also exist with 
relatively minor changes of alloy com- 
position (i.e., between a weld metal and 
the base metal). Natural (i.e., an oxide 
coating on aluminum) or a protective 
coating may inhibit galvanic corrosion, 



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but in most instances the metals or al- 
loys must be selected on the basis of 
intrinsic resistance to corrosion. 

3) In transport tanks, the effects of galvanic 
corrosion are most noticeable at welds 
or at flanged and bolted connections 
that have been exposed to contact with 
a fluid that is conductive. 

g) Erosion/Corrosion 

This type of damage mechanism is generally 
attributed to the movement of a corrodent 
over a metal surface that increases the rate 
of attack due to mechanical wear and cor- 
rosion. This type of damage mechanism 
is generally characterized as having an 
appearance of smooth bottomed shallow 
pit, and may also exhibit a directional pat- 
tern or surface texture related to the path 
taken by the corrodent. This deterioration 
would normally occur at locations where 
the transport tank is filled or emptied. 

h) Crevice Corrosion 

1) Environmental conditions in a crevice 
can, with time, become different to 
those on a nearby clean surface. A more 
aggressive environment may develop 
within the crevice and cause local cor- 
rosion. Crevices corrosion commonly 
can be found in: 

a. Gasket surfaces; 

b. Lap joints; and 

c. Bolts and flanges. 

2) Crevice corrosion can also be caused 
by dirt deposits, corrosion products, 
scratches in paint, etc. 

3) To avoid or greatly reduce corrosion, 
the owner-user of transport tanks, when 
having a transport tank manufactured, 
can specify materials and protection 



methods (such as coating). By imple- 
menting proper selection of materials 
and protection methods, corrosive at- 
tack in transport tanks can be predicted 
and controlled. However, there may be 
unexpected failures as a result of one 
or more of the following: 

a. Poor choice of materials used in 
transport tank repairs or new con- 
struction; 

b. Operating conditions different from 
those anticipated in service; 

c. Defective fabrication; 

d. Improper design; 

e. Inadequate maintenance; and 

f. Defective material. 

S6.6.4 FAILURE MECHANISMS 

There are various failure mechanisms that can 
result in cracks or loss of structural integrity 
to transport tanks. The more common failure 
mechanisms described below are fatigue, 
mechanical, thermal, and corrosion induced 
brittle fracture and hydrogen embrittlement, 
as a result of poor handling practices during 
welded repairs. 

a) Fatigue — Stress reversals (such as cyclic 
loading) in parts of transport tank equip- 
ment are common, particularly at points 
of high secondary stress. These stresses 
can originate adjacent to locations of weld 
repairs and from over the road vibratory 
stresses. If stresses are high and reversals 
frequent, failure of parts may occur because 
of mechanical fatigue crack propagation. 
Fatigue failures in transport tanks may also 
result from exposure to cyclic temperature 
and pressure changes. Locations where met- 
als having different thermal coefficients of 



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INSPECTI C3NI 



expansion that are joined by welding may 
be susceptible to thermal fatigue upon ex- 
posure to service temperature variations. 

1) In specific cases where the combined 
effects of exposure to a corrosive en- 
vironment and cyclic loading occur 
together in a transport tank, the damage 
mechanism that can occur is corrosion 
assisted fatigue or simply corrosion 
fatigue. 

2) Corrosion fatigue crack propagation 
typically occurs along a straight direc- 
tion, with minimal branching. Some 
sources of fatigue crack initiation are: 

a. At sharp corners; 

b. At openings in the transport tank; 
and 

c. At structural attachments. 

b) Temperature — At subfreezing tempera- 
tures, water and some chemicals handled 
in transport tanks may freeze and cause 
failure. Carbon and low-alloy steels may 
be susceptible to brittle fracture, even at 
ambient temperatures. A number of failures 
have been attributed to brittle fracture of 
steels that were exposed to temperatures 
below their ductile-to-brittle (DBTT) transi- 
tion temperature during a pressure test or 
hydrostatic test. However, most brittle frac- 
tures have occurred on the first application 
of a particular stress level (that is, the first 
hydrostatic test or overload). 

1) Special attention should be given to 
low-al loy steels because they are prone 
to temper embrittlement, which can 
result in a loss of toughness. 

a. Temper embrittlement is defined as 
a loss of ductility and notch tough- 
ness due to postweld heat treatrnenT 
or high temperature service, above 
370°C (700°F). 



c) Hydrogen Embrittlement — A loss of 
strength and/or ductility in steels caused by 
atomic hydrogen dissolved in the steel. It 
is a low temperature phenomenon, seldom 
encountered above 95°C (200°F), and most 
often occurs as a result of hydrogen evolved 
from aqueous corrosion reactions or hy- 
drogen generated during welding. Weld 
underbead cracking (also know as delayed 
cracking and cold cracking) is also a form 
of hydrogen embrittlement; however, in this 
case, the hydrogen comes from the weld- 
ing operation rather than from a corrosion 
reaction. 

1) Weld underbead cracking is caused 
by hydrogen dissolved in a hard, high 
strength weld heat-affected zone. Use 
of low hydrogen welding practices to 
minimize dissolved hydrogen, and/or 
use of high preheat, and/or postweld 
heat treatment to reduce heat-affected 
zone hardness, will reduce the likeli- 
hood of weld underbead cracking in 
susceptible steel. 

2) Hydrogen embrittlement is reversible 
as long as no physical damage, e.g., 
cracking, has occurred in the steel. If 
the atomic hydrogen is removed from 
the steel before any damage occurs, 
for example by heating for a short time 
in the absence of hydrogen between 
150°C (300°F) and 205°C (400°F), 
normal mechanical properties will be 
restored. 

3) Welding procedures, repair methods, 
and inspection procedures must in- 
clude careful consideration of poten- 
tial failure in corrosive environments, 
including the various forms of hydrogen 
embrittlement. 

d) Stress Corrosion Cracking (SCC) — Crack- 
ing of a metal caused by the combined ac- 
tion of stress and a corrosive environment. 
SCC only occurs with specific combina- 
tions of metal and environment. The stress 



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required may be either applied or residual. 
Examples of stress corrosion cracking in- 
clude chloride stress corrosion cracking 
of stainless steels in hot, aqueous chloride 
solutions; caustic cracking of carbon steel 
in hot sodium hydroxide solutions, and 
ammonia stress corrosion cracking of brass 
in ammonia solutions (season cracking). 

1 ) Corrosivity alone is not a good indicator 
of the likelihood of a particular environ- 
ment to cause SCC in a particular metal. 
Solutions that are highly corrosive to a 
material almost never promote SCC. 

2) The principal variables affecting SCC 
are tensile stress, service temperature, 
solution chemistry, duration of expo- 
sure, and metal properties. Removing 
any one of these parameters sufficiently 
can reduce or eliminate the possibility 
of SCC occurring in service. 



S6.7 CLASSIFICATION BOUNDARIES 

a) Transport tanks are classified as Class 1, 
Class 2, and Class 3. The classification is 
established by the applicable Modal Ap- 
pendix of Section XII of the ASME Boiler 
and Pressure Vessel Code. Also contained in 
the Modal Appendix is the type of Inspec- 
tor, i.e., Authorized Inspector, Qualified 
Inspector, and Certified Individual, that is 
permitted to perform the applicable fabri- 
cation inspection of the transport tank, i.e., 
cargo tank, tank car, portable tank, and 
ton tank. The classification of the transport 
tank, except for continued service inspec- 
tions determines the code of construction 
requirements for repairs or modifications. 



S6.8 PRESSURE, TEMPERATURE, AND 

CAPACITY REQUIREMENTS FOR 

TRANSPORT TANKS 

a) Section XII has established pressure, tem- 
perature, and maximum thickness require- 
ments for transport tanks as follows: 



1) Pressure: full vacuum to 208 bar (full 
vacuum to 3,000 psia); 

2) Temperature: -269°C to 343°C (-452°F 
to 650°F); and 

3) Maximum material thickness: 38 mm 
(1-1/2 in.). 

b) Transport tanks manufactured prior to the 
adoption of ASME Section XII by the Com- 
petent Authority were manufactured in 
accordance with ASME Section VIII, Div. 1 . 
Transport tanks manufactured to this Code 
were required to be stamped with the "U" 
Code Symbol Stamp in accordance with 
Section VIII, Div. 1, if the design pressure 
of the transport tank was 35 psi (241 kPa) 
(depending on material being transported) 
and greater. If the design pressure was less 
than 35 psi (241 kPa)(depending on the 
media being transported), the transport 
tank was constructed in accordance with 
Section VIII, Div. 1, but not stamped with 
the "U" Code Symbol Stamp. 

c) For these transport tanks, the requirements 
established in this part for continued service 
inspection, repairs, or modifications shall 
apply, unless specifically exempted by the 
DOT. 



S6.9 REFERENCE TO OTHER CODES 

AND STANDARDS 

Other existing inspection codes, standards, and 
practices pertaining to the continued service 
inspection, i.e., CFR 49, Parts 100 through 
1 85, ASME Section XII, etc., of transport tanks 
can provide useful information and references 
relative to the inspection techniques listed in 
this appendix. Additionally, supplementary 
guidelines for assisting in the evaluation of in- 
spection results and findings are also available. 
Some acceptable requirements and guidelines 
are as follows: 

a) American Society of Mechanical Engineers 
— ASME Boiler and Pressure Vessel Code, 



2 1 2 



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INSPECTION 



Section VIII, Div. 1 (Rules for Construction 
of Pressure Vessels). 

b) American Society of Mechanical Engi- 
neers: 

1 ) ASME Section V (Nondestructive Exami- 
nation) 

2) ASME Section IX (Welding and Brazing 
Qualifications). 

c) Code of Federal Regulations, Title 49, Parts 
100 through 185, Transportation. 

d) American Petroleum Institute — API 579, 
Fitness for Service. 

e) ADR 2003, European Agreement Concern- 
ing the International Carriage of Dangerous 
Goods by Road. (Published by the UN Eco- 
nomic Commission for Europe, Informa- 
tion Service, Palais des Nations, C7-1211 
Geneve, Suisse). 

f ) CG A 6-4 . 1 , Cleaning Equipmen t for Oxygen 
Service. 

g) CGA S-1 .2, Pressure Relief Device Stan- 
dard, Part 2: Cargo and Portable Tanks for 
Compressed Gases. (Published by the Com- 
pressed Gas Association, Inc. [CGA], 4221 
Walney Road, Chantilly, VA 20151). 

h) IMDG Code 2002, International Maritime 
Dangerous Goods Code (including Amend- 
ment 3 1 -02 . (Publ ished by the International 
Maritime Organization [IMO], 4 Albert 
Embankment, London, SE1 7SR). 

i) RID 2003, Carriage of Dangerous Goods. 
(Published by the Intergovernmental Orga- 
nization for International Carriage by Rail 
[OTIF], Gyphenhubeliweg 30, C7-3006 
Berne, Suisse). 



j) United Nations Recommendations on the 
Transport of Dangerous Goods - Modal 
Regulations. (Published by the United Na- 
tions Publications, 2 UN Plaza, New York, 
New York 10017). 

k) SSPC Publication #91-12, Coating and 
Lining Inspection Manual. (Published by 
Steel Structures Painting Council, 4400 Fifth 
Avenue, Pittsburgh, PA 15212-2683). 



S6.10 



CONCLUSION 



a) During any continued service inspections 
or tests of transport tanks, performed by the 
Registered Inspector, the actual operating 
and maintenance requirements as speci- 
fied in this appendix shall be satisfied. The 
Registered Inspector shall determine, based 
on the applicable requirements of the Code 
of Federal Regulations, Title 49, Parts 100 
through 185, and this appendix, whether 
the transport tank can continue to be safely 
operated. 

b) Defects or deficiencies in the condition, 
operation, and maintenance requirements 
of the transport tank, including piping, 
valves, fittings, etc., shall be discussed with 
the owner or user of the transport tank at the 
time of inspection. Defects or deficiencies 
shall be corrected using the appropriate 
methods prior to returning the transport 
tank to service. 



S6.11 PERSONNEL SAFETY AND 

INSPECTION ACTIVITIES 

a) Proper inspection of transport tanks may 
require pre-inspection planning. This plan- 
ning should include development of an in- 
spection plan that will satisfy the applicable 
technical requirements of this part, the 



z 1 3 



NATIONAL BOARD INSPECTION CODE • PART Z 



INSPECTION 



Code of Federal Regulations, Title 49, Parts 
100 through 185, Transportation, and ap- 
propriate safety considerations. The inspec- 
tion plan should also include the applicable 
failure and deterioration mechanisms, and 
inspection methods and the requirements 
of the applicable Competent Authority. 

b) This Supplement describes pre-inspection 
and post-inspection activities applicable to 
all transport tanks. Specific inspection re- 
quirements for transport tanks are identified 
in Sections S6. 13 for Cargo Tanks, S6.14for 
Portable Tanks, S6.15 for Ton Tanks. 

c) Personnel safety is the joint responsibility 
of the owner or user and the Registered 
Inspector. All applicable safety regulations 
shall be followed. This includes, if appli- 
cable, all governmental rules and regula- 
tions. Owner's or user's personnel safety 
programs and/or safety programs by the 
Inspector's employer, or similar regulations 
such as confined space requirements also 
apply. 



S6.1 2 TRANSPORT TANK ENTRY 

REQUIREMENTS 

a) No transport tank shall be entered until it 
has been properly prepared for inspection. 
The owner or user and the Inspector shall 
determine that the transport tank may be 
entered safely. This shall include: 

1) Potential hazards associated with the 
entry into the transport tank have been 
identified by the owner or user and are 
brought to the attention of the Inspec- 
tor, along with acceptable means or 
methods for mitigating each of these 
hazards; 

2) Coordination of entry into the transport 
tank by the Inspector and the owner or 
user representative(s) working in or near 
the transport tanks; 



3) If personal protective equipment is re- 
quired to enter the transport tank, the 
necessary equipment is available, and 
the Inspector is properly trained in its 
use; and 

4) An effective energy isolation program is 
in place and in effect that will prevent 
the unexpected release of energy or 
media to enter the transport tanks. 

b) The Inspector shall be satisfied that a safe 
atmosphere exists before entering the trans- 
port tank. The oxygen content of breathable 
atmosphere shall be between 19.5% and 
23.5%. 

c) The Inspector shall not be permitted to enter 
an area if toxic, flammable, or inert gases 
or vapors are present and above acceptable 
limits without proper personal protective 
equipment. Protective equipment may 
include, among other items, protective 
outer clothing, gloves, eye protection, foot 
protection, or respirators. 

d) The Inspector shall have proper training 
governing the selection and use of any 
personal protective clothing and equipment 
necessary, particularly related to respiratory 
protection if the testing of the atmosphere of 
the transport tank reveals any hazards. This 
requirement is to ensure that the inspection 
may be performed safely. 



S6.12.1 PRE-INSPECTION ACTIVITIES 

a) Prior to conducting the inspection, a review 
of the history of the transport tank and a 
general assessment of current conditions 
shall be performed. This shall include a 
review of information, such as: 

1 ) Date of the last inspection; 

2) Current Inspection Certificate; 



Z 1 4 



NATIONAL BOARD INSPECTION CODE • PART 2 



INSPECTION 



3) ASME Code Name Plate and /or Speci- 
fication; 

4) If applicable, National Board registra- 
tion number; 

5) Serial number of identification marking 
of the transport tank; 

6) Operating conditions and normal con- 
tents of the transport tank; 

7) Previous inspection report or inspection 
certificates; 

8) Records of wall thickness checks, es- 
pecially where corrosion is a consid- 
eration; and 

9) Observations of the condition of the 
complete transport tank, including, 
piping, fitting, valves, etc. 

b) The fol lowi ng activities shou Id be performed 
as required to support the inspection: 

1) Verify the pressure gages, thermom- 
eters, and indicating devices are in 
proper calibration; 

2) Ensure that all overpressure protection 
devices are in proper operation, and 
that they are operating as designed; 
and 

3) Ensure that all structural attachments 
are free of defects and are operating as 
designed. 



S6.12.2 PREPARATION FOR INTERNAL 
INSPECTION 

The owner or user has the responsibility to 
prepare a transport tank for internal inspection. 
Requirements for safety including occupational 
safety and health regulations (federal, state, 
local, or other), the owner's or user's own 
safety program and the safety programs of the 



Inspector's employer are applicable for inspec- 
tions. The transport tank shall be prepared in 
the following manner or as deemed necessary 
by the Inspector. 

a) When a transport tank is connected to a 
common header with other transport tanks 
or in a system where liquids or gases are 
present, the transport tank shall be isolated 
by closing, locking, and/or tagging stop 
valves in accordance with the owner's or 
user's procedures. 

b) When toxic or flammable materials are in- 
volved, additional safety precautions should 
require removing pipe sections or blanking 
pipelines before entering the transport tank. 
The means of isolating the transport tank 
shall be acceptable to the Inspector and in 
compliance with applicable occupational 
safety and health regulations. 

c) The transport tank shall be allowed to cool 
or warm to ambient temperature at a rate 
to avoid damage to the transport tank. 

d) The transport tank shall be drained of all 
liquid and shall be purged of any toxic or 
flammable gases or other contaminants 
that were contained in the transport tank. 
Mechanical ventilation using a fresh air 
blower or fan shall be started after the 
purging operation and maintained until 
all pockets of "dead air" that may contain 
toxic or flammable or inert gases are re- 
duced to acceptable limits. During the air 
purging and ventilation of the transport 
tank involved with flammable gases, the 
concentration of the vapor in air should 
pass through the flammable range before a 
safe atmosphere is obtained. All necessary 
precautions shall be taken to eliminate the 
possibility of explosion or fire. 

e) Manhole, if applicable, and handhole 
plates, washout plugs, inspection plugs, 
and any other item requested by the Inspec- 
tor shall be removed. 



2 1 5 



NATIONAL BOARD INSPECTION CODE • PART Z 



INSPECTION 



The Inspector shall not enter a transport 
tank until all safety precautions have been 
taken. The temperature of the transport tank 
shall be such that the inspection personnel 
will not be exposed to excessive heat or 
cold. The transport tank should be cleaned 
as necessary. 

A qualified person (attendant) shall remain 
outside the transport tank at the point of 
entry while the Inspector is inside and 
shall monitor activities inside and outside 
and communicate with the Inspector as 
necessary. The attendant shall have means 
of summoning rescue assistance if needed 
and to facilitate rescue procedures for those 
inside the transport tank without personally 
entering the transport tank. 

Note: If a transport tank has not been prop- 
erly prepared for an internal inspection, the 
Inspector shall decline to make the inspec- 
tion. 



S6.12.3 POST-INSPECTION ACTIVITIES 

a) Any defects or deficiencies in the condition, 
operation, and maintenance practices of 
the transport tank and auxiliary equipment 
shall be reported to the owner or user, in- 
cluding recommendations for correction. 

b) Documentation of inspections shall con- 
tain pertinent data such as a description 
of the transport tank, classification (Class 
1, 2, or 3), the transport tank identifica- 
tion number, inspection intervals, date of 
inspection, type of inspection, or type of 
test performed, and any other information 
required by the Competent Authority. The 
Inspector shall sign, date, and note any 
deficiencies, comments, or recommenda- 
tions on the inspection report. The Inspector 
should retain and distribute copies of the 
inspection report as required. 



S6.13 INSPECTION AND TESTS OF 

CARGO TANKS 

All cargo tanks shall be examined and tested 
at frequencies specified in Table S6.13. The 
examination and tests shall provide for a visual 
external, visual internal, leakage test, pressure 
test, thickness test, and lining test. It should 
be noted that the information in Table S6.13 
is a summary of United States Code of Federal 
Regulations, Title 49, Part 180. The user shall 
compare the requirements provided with Part 
1 80 to ensure full compliance. 



S6.13.1 VISUAL EXTERNAL INSPECTION 

a) Visual inspections are required of the 
complete cargo tank as required in Table 
S6.13. The visual inspection shall include 
the heads, shell, nozzle connections, 
support attachments, all welded seams 
(longitudinal and circumferential), nozzle 
attachment welds, support, piping, appur- 
tenances, structural attachments, and any 
attachment welds for possible defects. The 
visual inspection shall include a thorough 
examination for scratches that affect the 
pressure containing capabilities of the car- 
go tank, dents, leaks, distortions, corroded 
or abraded areas, and any other condition 
that would affect the safe operation of the 
cargo tank. If the cargo tank is able to be 
externally inspected, this must be noted in 
the inspection report of the cargo tank. 

b) If the cargo tank is insulated or the cargo 
tank is insulated and equipped with an 
internal lining, the following inspections 
shall be performed: 

1) Insulated cargo tanks — If the insula- 
tion on the cargo tank precludes a 
complete and thorough external visual 
inspection, the cargo tank shall be sub- 
jected to an internal visual inspection, if 
equipped with a manhole or inspection 
openings. This inspection shall include 
all internal surfaces, including welds, 



z i 6 



NATIONAL BOARD INSPECTION CDDE • PART 2 



INSPECTION 



Table S6.1 3 

Periodic Inspections and Tests 



Test or Inspection 

(cargo tank specification, configuration, and service) 


Date by which first test 
must be completed 
(see Note 1) 


interval period 
after first test 


External Visual inspection 


All cargo tanks designed to be loaded by vacuum with 
full opening rear heads 


September 1, 1991 


6 Months 


All other cargo tanks 


September 1, 1991 


1 Year 


Internal Visual Inspection 


All insulated cargo tanks, except MC 330, 
MC 331, & MC 338 (See Note 4) 


September 1, 1991 


1 Year 


All cargo tanks transporting lading corrosive to the tank 


September 1, 1991 


I Year 


All other cargo tanks, except MC 338 


September 1, 1995 


5 Years 


Lining Inspection 


All lined cargo tanks transporting lading corrosive 
to the tank 


September 1, 1991 


1 Year 


Leakage Test 


MC 330 and MC 331 cargo tanks in chlorine service 


September 1, 1991 


2 Years 


All other cargo tanks, except MC 338 


September 1, 1991 


1 Year 


Pressure Test 


Hydrostatic or Pneumatic (see Notes 2 and 3) 


— 


— 


All cargo tanks which are insulated with no manhole or 
insulated and lined, except MC 338 


September 1, 1991 


1 Year 


All cargo tanks designed to be loaded by vacuum with 
full opening heads 


September 1 , 1 992 


2 Years 


MC 330 and MC 331 cargo tanks in chlorine service 


September 1 , 1 992 


2 Years 


All other cargo tanks 


September 1, 1995 


5 Years 


Thickness lest 


All unlined cargo tanks transporting material corrosive to 
the tank, except MC 338 


September 1 , 1 992 


2 Years 


Note 1 : If a cargo tank is subject to an applicable inspection or test requirement under the regulations in effect 
on December 30, 1 990, and the due date (as specified by a requirement in effect on December 30, 1 990) for 
completing the required test occurs before the compliance date listed in the Table, the earlier date applies. 
Note 2: Pressure testing is not required for MC 300 and MC 331 cargo tanks in dedicated sodium metal service. 
Note 3: Pressure testing is not required for uninsulated lined cargo tanks with a design pressure of MAWP 1 5 
psig or less, which receive an external visual inspection and lining inspection at least once each year. 
Note 4: Insulated cargo tanks equipped with manholes or inspection openings may receive either an internal 
visual inspection in conjunction with the external visual inspection or a hydrostatic or pneumatic test of the 
cargo tank. 



2 1 V 



NATIONAL BOARD INSPECTION CDDE • PART 2 



INSPECTION 



nozzle attachments, and, if equipped, 
baffles, internal stiffeners, surge protec- 
tion devices for defects, corrosion, and 
missing or loose attachment; 

2) Lined, coated, or if the cargo tank is 
so designed to preclude an internal 
visual inspection — If the cargo tank is 
externally lined, coated, or of a design 
that would prevent a complete and 
thorough external visual examination, 
the internal areas of the cargo tank that 
are not obstructed by the lining or coat- 
ing shall be internally inspected; 

3) Lined, coated, or if the cargo tank is 
so designed to preclude access to the 
internal surfaces — The cargo tank shall 
be subjected to a hydrostatic or pneu- 
matic test in accordance with S6.13.6 
of this section; 



TableS6.13.1-a 

fnservice Minimum Thicknesses for Steel and Steel 



4) All corroded or abraded areas of a cargo 
tank wall must be thickness tested in 
accordance with the following proce- 
dures: 

a. Measurements must be made us- 
ing a device capable of accurately 
measuring thickness within ± 0.002 
of an inch (± 0.051 mm); 

b. Any individual performing thickness 
testing must be trained in the proper 
use of the thickness testing device in 
accordance with the testing device 
manufacturer's instructions; 



c. 



The minimum thickness require- 
ments for the heads, shell baffle, 
and bulkhead, when used as tank 
reinforcement, shall meet the mini- 
mum thickness requirements for in- 
service requirements for cargo tank 
specifications MC 300, MC 303, 
MC 304, MC 306, MC 307, MC 



Alloys 



Minimum manufactured thickness (US "Manufacturers' 
Standard Cage for Steel Sheets" or inches) 


Nominal decimal 
equivalent, inches 
(mm) 


Inservice minimum 
reference, inches 

(mm) 


1 9 gage 


1.06(0.0418) 


0.97 (0.038) 


1 8 gage 


1.21 (0.0478) 


1.09 (0.043) 


1 7 gage 


1.37(0.0538) 


1.22 (0.048) 


1 6 gage 


1.52 (0.0598) 


1.37(0.054) 


1 5 gage 


1.71 (0.0673) 


1.55 (0.061) 


14 gage 


1.90(0.0747) 


1.70(0.067) 


1 3 gage 


2.28(0.0897) 


2.06(0.081) 


1 2 gage 


2.66(0.1046) 


2.39 (0.094) 


1 1 gage 


3.04 it). I 196) 


2.74(0.108) 


1 gage 


3.42 (0.1345) 


3.07(0.121) 


9 gage 


3.80 10.14') 5) 


3.43 (0.135) 


8 gage 


4.18(0.1644) 


3.76 (0.148) 


7 gage 


4.55(0.1793) 


4.09(0.161) 


3/16 inch 


5 (0.1875) 


4.29(0.169) 


1/4 inch 


6 (0.2500) 


5.72 (0.225) 


5/16 inch 


8(0.3125) 


7.14(0.281) 


3/8 inch 


10(0.3750) 


8.59 (0.338) 



z i a 



NATIONAL BOARD INSPECTION CODE • PART Z 



INSPECTION 



S6.13.2 



310, MC 311 transport tanks, and 
MC 312 cargo tanks constructed 
of steel, steel alloys, aluminum, 
and aluminum alloys are based on 
90% of the minimum manufac- 
tured thickness. Table S6.13.1-a, 
provides minimum inservice mini- 
mum thicknesses for steel and steel 
alloys. Table S6.1 3.1 -b provides 
minimum thicknesses for aluminum 
and aluminum alloys. 



INSPECTION OF PIPING, 
VALVES, AND MANHOLES 



a) The cargo tank piping, valves, and gaskets 
must be carefully inspected for corroded ar- 
eas and the piping system and valve attach- 
ment welds or threads must be inspected 
for corrosion, leakage, or any other defects 
that might render the cargo tank unsafe for 



transportation service. This examination 
shall include: 

b) All devices for securing manhole covers 
must be in satisfactory working condition, 
and the area must not show any evidence 
of leakage at either the manhole cover or 
the manhole gasket. 

1) When inspecting gaskets on any full 
opening of the cargo tank, the inspector 
should visually examine the gasket for 
defects to include cracks and/or splits 
that may prevent the gasket material 
from sealing properly. 

2) If the gasket shows any evidence of cuts 
or cracks that are likely to cause failure, 
the gasket shall be replaced. 

c) All emergency devices and valves includ- 
ing self-closing stop valves, excess flow 



Table S6.1 3.1 -b 

Inservice Minimum Thicknesses for Aluminum and Aluminum Alloys 



Minimum manufactured thickness, inches 

(mm) 


Inservice minimum thickness, inches (mm) 


1 .98 (0.078; 


1.78(0.070! 


2.21 (0.087) 


1.98(0.078) 




2.44 (0.096) 


2.18(0.086) 


2.77(0.109) 


2.49(0.098) 


3.30(0.130) 


2.97(0.117) 


3.58(0.141) 


3.23 (0.127) 




3.84 (0.1 .SI) 


3.45 (0.136) 


4.37(0.172) 


3.94(0.1 55) 


4.39(0.173) 


3.96 1.0.156) 


4.93 (0.194) 


4.44(0.175) 


5.49(0.216) 


4.93 (0.194) 


6.02 (0.237) 


5.41 (0.213) 


6.86(0.270) 


6.17(0.243) 


9.14(0.360) 


8.23 (0.324) 


1 1 .40 (0.450) 


1 0.30 (0. 405) 


13.70(0.540) 


12.30(0.486) 



Z 1 9 



NATIONAL BOARD INSPECTION CODE • PART Z 



INSPECTION 



valves, and remote closure devices must 
be free of corrosion, distortion, erosion, 
and any external damage that will prevent 
safe operation of the cargo tank. Remote 
closure devices and self-closing stop valves 
must be operated during inspection to 
demonstrate that the devices are operating 
as designed. 

d) Any missing bolts, nuts, and fusible links 
or elements shall be replaced. Loose bolts 
and nuts must be tightened. 

e) All re-closing pressure relief valves shall 
be externally inspected for any corrosion 
or damage that might prevent the device 
from operating as designed. 

1 ) All re-closing pressure relief valves on 
cargo tanks carrying lading corrosive 
to the pressure relief valve shall be 
removed from the cargo tank for inspec- 
tion and testing. 

2) Each re-closing pressure relief valve 
required to be removed and tested as 
specified in (e)(1) above must open at 
the required test pressure and reseat to 
a leak-tight condition at 90% of the set- 
to-discharge pressure or the pressure 
prescribed for the applicable cargo tank 
specifications. 



S6.13.3 INSPECTION OF 

APPURTENANCES AND 
STRUCTURAL ATTACHMENTS 

a) Major appurtenances, as defined in CFR 
49, 1 80.407 (d)(2)(viii), include but are not 
limited to suspension system attachments, 
connecting structures, and those elements 
of the upper coupler (kingpin) assembly that 
can be inspected without dismantling the 
upper coupler (kingpin) assembly. Major 
appurtenances shall be inspected for any 
corrosion or damage that might prevent safe 
operations. 



b) If the cargo tank transports lading that is 
corrosive to the cargo tank, the upper cou- 
pler (kingpin) assembly must be inspected 
at least once in a two year period. The up- 
per coupler (kingpin) shall be removed for 
inspection of the following: 

1 ) Corroded and abraded areas; 

2) Dents; 

3) Distortions; 

4) Weld failures; and 

5) Any other condition that might render 
the cargo tank unsafe for transportation 
service. 

c) If the cargo tank is constructed of mild or 
high strength low alloy steel and employs 
ring stiffeners or other appurtenances that 
create air cavities adjacent to the ring stiff- 
eners or other appurtenances to the cargo 
tanks shell and these areas cannot be visu- 
ally externally inspected, then the following 
shall be performed: 

1) A thickness test on the stiffener rings 
shall be performed at least once every 
two years of at least four symmetrically 
distributed readings to establish an 
average thickness for the ring stiffener 
or appurtenance. The thickness require- 
ments are specified in Tables S6.1 3.1 -a 
or S6.1 3.1 -b, as applicable; 

2) If any of the thickness testing readings 
for the ring stiffeners are less than the 
average thickness by more than 10%, 
thickness testing must be performed 
from inside the transport tank on the 
area of the tank wall covered by the 
appurtenance or ring stiffener. If the re- 
sults of the thickness test of the transport 
tank fail to conform to the minimum 
thickness requirements prescribed for 
the design as manufactured, the tank 



Z2D 



NATIONAL BOARD INSPECTION CODE 



INSPECTION 



must be repaired or removed from haz- 
ardous material service. The owner of 
the transport tank can de-rate the tank 
to transport authorized material and 
reduced maximum weight of lading, re- 
duce pressure, or a combination thereof 
under the following conditions: 

a. The reduced loadings based on the 
cargo tanks design conditions and 
material thicknesses are appropri- 
ate for the reduced loading condi- 
tions. This reduced loading shall be 
certified by a Design Certifying En- 
gineer, and a revised manufacturer's 
certificate shall be issued reflecting 
these reduced loading conditions; 

b. The cargo tank motor vehicle's 
manufacturer's nameplate shall 
be revised to reflect the reduced 
limits; 

c. If (a) and (b) above can not be sat- 
isfied, the owner of the cargo tank 
should not return the cargo tank 
to hazardous material service. The 
owner shall remove, or obliterate, 
or in a secure manner cover the 
tank's specification plate; and 

d. The inspector shall record the re- 
sults of the thickness test on the 
cargo tank's inspection report. 



S6.13.4 VISUAL INTERNAL INSPECTION 

When performing an internal visual inspection 
of a cargo tank and the cargo tank is equipped 
with a manhole or an inspection opening, the 
inspector shall examine the internal surfaces for 
corroded and abraded areas, dents, distortions, 
defects in welds, and any other conditions that 
might render the cargo tank unsafe for trans- 
portation service. As a minimum the inspection 
shall include: 

a) The cargo tank shell and heads; 



b) If equipped, the cargo tank corrosion- 
resistant liner must be inspected at least 
once a year. The inspection shall include 
procedures for rubber liners and liners 
other than rubber (elastomeric materials). 
The requirements for lining inspections are 
provided in Table S6.13.4 of this section; 
and 

c) If the cargo tank is not equipped with a 
manhole or inspection opening, the cargo 
tank shall be subjected to a hydrostatic or 
pneumatic test as provided in Table S6.1 3.4 
of this section. 



S6.13.5 LINING INSPECTIONS 

Cargo tank linings include rubber linings and 
linings other than rubber (elastomeric materials) 
that are used to protect the tank from corrosion 
or other harmful effects of the lading material 
being transported. The inspection requirements 
are: 

a) Rubber linings must be inspected for holes 
by using a high frequency spark tester, as 
described in this section. If holes are found, 
they must be repaired using equipment 
and procedures prescribed by the lining 
manufacturer or lining installer; 

b) Linings other than rubber (elastomeric ma- 
terials) must be inspected and tested in ac- 
cordance with procedures using equipment 
and procedures prescribed by the lining 
manufacturer or lining installers; and 

c) If degraded or defective areas of the cargo 
tank lining are discovered, the lining in 
these areas shall be removed and the thick- 
ness of the cargo tank wall area under the 
lining defect shall be tested in accordance 
with the following: 

1) Measurements shall be made using a 
device capable of accurately measuring 
thickness to within ± 0.002 of an inch 
(± 0.051 mm); 



22 1 



NATIONAL BOARD INSPECTION CODE • PART Z 



INSPECTION 



Table S6.1 3.4 

Periodic Inspections and Tests 



Test or Inspection 

(cargo tank specification, configuration, and service) 


Test and Inspection Interval 
After Original Certification 
Date 


External Visual Inspection 


All cargo tanks designed to be loaded by vacuum with 
full opening rear heads 


6 Months 


All other cargo tanks 


1 Year 


Internal Visual Inspection 


All insulated cargo tanks, except MC 330, 
MC331,&MC338 


1 Year 


All cargo tanks transporting lading corrosive to the tank 


1 Year 


All other cargo tanks, except MC 338 


5 Years 


Lining Inspection 


All lined cargo tanks transporting lading corrosive 
to the cargo tank 


1 Year 


Leakage Test 


MC 330 and MC 331 cargo tanks in chlorine service 


2 Years 


All other cargo tanks, except MC 338 


1 Year 


Pressure Test 

(Note 1 : sodium metal; Note 2: MAWP < 1 5 psig) 


All cargo tanks which are insulated with no manhole or 
insulated and lined, except MC 338 


1 Year 


All cargo tanks designed to be loaded by full vacuum 
with full opening in the rear head of the cargo tank 


2 Years 


MC 330 and MC 331 cargo tanks in chlorine service 


2 Years 


All other cargo tanks 


5 Years 


Thickness Test 


All unlined cargo tanks in corrosive service, 
except MC 338 


2 Years 


Note 1 : Pressure testing is not required for MC 300 and MC 331 cargo tanks in dedicated 
sodium metal service. 

Note 2: Pressure testing is not required for uninsulated lined cargo tanks with a design pres- 
sure of MAWP 1 5 psig or less, which receive an external visual inpsection and lining inspec- 
tion at least once each year. 



ZZZ 



NATIONAL BOARD INSPECTION CODE • PART Z 



INSPECTION 



2) The individuals performing the thick- 
ness test must be trained in the proper 
use of the thickness testing device in 
accordance with the manufacturer's 
instructions; and 

3) The minimum inservice thickness re- 
quirements for series MC 300 cargo 
tanks for steel and steel alloy and alu- 
minum and aluminum alloy material 
is specified in Tables S6.13.1-a and 
S6.13.1-b. 



S6.13.6 PRESSURE TESTS 

Cargo tanks may be tested by either the hy- 
drostatic or pneumatic test method. When 
performing a pressure test, the test procedure 
shall include the test method (hydrostatic or 
pneumatic) used for the cargo tank, and the 
test shall include all appurtenance, all baffles, 
bulkheads, and upper coupler (fifth wheel) that 
comprise the cargo tank and shall be pressure 
tested at pressures established in Table S6. 13.6. 



The pressure test procedure shall include the 
following: 

a) The pressure test shall be performed in ac- 
cordance with a test pressure that includes 
provision for the inspector to perform an 
internal and external visual inspection of 
all surfaces of the cargo tank. For MC 338 
cargo tanks, and cargo tanks not equipped 
with a manhole, an internal visual inspec- 
tion is not required. 

1) The visual external inspection shall 
be conducted while the cargo tank is 
under test pressure. 

2) The visual internal inspection shall 
be conducted after the pressure test is 
completed. 

b) When performing the pressure test all self- 
closing pressure relief valves, including 
emergency relief vents, and normal vents 
shall be removed for inspection and test, 
except for line safety devices that may be 
removed or left in place. 



Table S6.1 3.6 

Pressure Test Requirements 






Cargo Tank Specification 


Test Pressure 




MC 300, MC 301, MC 302, MC 303, 
MC 305, and MC 306 


3 psig (20.7 kPa) or design pressure, 
whichever is greater 


MC 304 and MC 307 


40 psig (275.8 kPa) or 1.5 times design 
pressure, whichever is greater 


MC310, MC311,andMC312 


3 psig (20.7 kPa) or 1 .5 times design pressure, 
whichever is greater 


MC330andMC331 


1 .5 times either MAWP or the re-rated 
pressure, whichever is applicable 


MC338 


1 .25 times either MAWP or the re-rated 
pressure, whichever is applicable 


DOT 406 


5 psig (34.5 kPa) or 1 .5 times the MAWP, 
whichever is greater 


DOT 407 


40 psig (275.8 kPa) or 1 .5 times the MAWP, 
whichever is greater 


DOT 412 


1.5 times the MAWP 









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NATIONAL BOARD INSPECTION CODE • PART 2 



INSPECTION 



1) Each self-closing pressure relief valve 
that is an emergency relief vent shall 
be capable of opening at the required 
set pressure and seat to a leak-tight 
condition at 90% of the set-to-discharge 
pressure, or the pressure prescribed for 
the applicable cargo tank. It should be 
noted that self-closing pressure relief 
valves not tested or failing the pressure 
test must be repaired or replaced; 

2) Normal vents (1 psig vents) shall be 
tested according to the testing criteria 
established by the valve manufacturer. 

c) If the cargo tank is not carrying a corrosive 
lading, all areas that are covered by the 
upper coupler (fifth wheel) assembly must 
be inspected for corroded, abraded areas, 
dents, distortions, defects in welds, and any 
other condition that might render the tank 
unsafe for transport service. The upper cou- 
pler (fifth wheel) assembly must be removed 
from the cargo tank for this inspection. 

d) If the cargo tank motor vehicle has multiple 
cargo tanks, each cargo tank shall be tested 
separately. The adjacent cargo tanks shall 
be empty and at atmospheric pressure. 

e) When performing the hydrostatic or pneu- 
matic test, the following requirements shall 
be specified in the test procedure: 

1) All closures, except the pressure relief 
device shall be in place during the 
test; 

2) All required loading and unloading 
venting devices that are rated less than 
the test pressure may be removed dur- 
ing the test, or: 



a. 



If the venting devices are not 
removed, the device shall be ren- 
dered inoperative by clamps, plugs, 
or other equally effective restrain- 
ing devices; 



b. The restraining devices shall not 
prevent detection of leaks or dam- 
age of the venting device and shall 
be removed immediately after the 
test. 



S6.1 3.6.1 HYDROSTATIC OR PNEUMATIC 
TEST METHOD 

a) The owner or user of the cargo tank may 
either apply the hydrostatic or pneumatic 
test method to satisfy the requirements of 
the pressure test specified in Table S6.1 3.4 
of this section. 

b) If the hydrostatic test method is used, the 
cargo tank shall be completely filled in- 
cluding, if equipped, its dome with water 
or other liquids having similar viscosity. 
During the hydrostatic test, the inspector 
shall: 

1 ) Ensure that the cargo tank is completely 
filled and free of any air pockets. During 
this operation, the liquid should flow 
freely out of the cargo tanks test vent; 

2) Ensure that the temperature of the test 
media does not exceed 1 00°F; 

3) Ensure that the test pressure can not 
exceed the test pressures specified in 
Table S6. 13.6; 

4) Ascertain that the test pressure shall 
be maintained for a minimum of 10 
minutes; and 

5) Visually examine the cargo tank for 
leakage, bulging or other defects. If any 
of the proceeding occurs, terminate the 
test, drain the cargo tank, and evaluate 
the cargo tanks capabilities for repair or 
replacement of the affected areas. 

c) If the owner and/or user elect to use the 
pneumatic test method, precaution should 



224- 



NATIONAL BOARD INSPECTION CODE ' PART 2 



INSPECTION 



be employed due the possibility of failure of 
the cargo tank under pneumatic test pressure 
conditions. The test area should be limited 
to the authorized personnel only and the 
test personnel shall be experienced in the 
pneumatic testing method. The pneumatic 
test pressure for the cargo tank shall be: 

1) gradually increased to one-half the test 
pressure; 

2) after reaching one-half the test pressure, 
the test pressure shall be increased at 
rate of approximately one-tenth of the 
test pressure until the test pressure is 
reached. The test pressure shall not 
exceed the test pressures specified in 
Table S6.13.6; 

3) when the test pressure is reached, the 
test pressure shall be held for a least 5 
minutes, then reduced to the MAWP of 
the cargo tank; 

4) at MAWP the inspector shall examine 
the cargo tank for any leakage, bulging, 
or any other defects; and 

5) visually examine the cargo tank for 
leakage, bulging, or other defects. If any 
of the preceeding occurs, terminate the 
test, drain the cargo tank of all air or 
inert gas, and evaluate the cargo tanks 
suitability for repairs or replacement of 
the affected areas. 



S6.1 3.6.2 PRESSURE TESTING INSULATED 
CARGO TANKS 

a) When pressure testing an insulated cargo 
tank, the insulations and jacketing are not 
required to be removed, unless it is not pos- 
sible to reach the test pressure and maintain 
a condition of pressure equilibrium after 
the test pressure is reached, or the vacuum 
integrity cannot be maintained in the insu- 
lation space. 



b) For MC 338 cargo tanks that transport re- 
frigerated liquid, flammable gas, or oxygen, 
if the cargo tank is opened for any reason, 
the cleanliness of the cargo tank shall be 
verified prior to closure as required by CFR 
Title 49, Part 178.338-1 5. 



S6.13.6.3 PRESSURE TESTING CARGO 

TANKS CONSTRUCTED OF 
QUENCHED AND TEMPERED 

STEELS 

When testing MC 330 and MC 33 1 cargo tanks 
constructed of quenched and tempered steels, 
in accordance with ASME Section XII, Modal 
Appendix 1, and for cargo tanks constructed 
prior to the adoption of ASME Section XII, 
Part UHTof ASME Section VIII, Div. 1, of the 
ASME Boiler and Pressure Vessel Code, or con- 
structed of other quenched and tempered steel, 
without postweld heat treatment, used for the 
transportation of anhydrous ammonia or any 
other hazardous material that are subject to 
stress corrosion cracking, and the transporta- 
tion of liquefied petroleum gas, the following 
is required: 

a) The cargo tanks must be subjected to an 
internal visual inspection of all internal 
surfaces of the cargo tank using the wet 
fluorescent magnetic particle examination 
method immediately prior to performing 
the required pressure test; 

b) The fluorescent magnetic particle exami- 
nation has to be performed in accordance 
with ASME Section V of the Boiler and 
Pressure Vessel Code; 

c) The required pressure test as specified in 
Table S6.1 3.4 shall be required. 



ZZ5 



NATIDNAL BOARD INSPECTION CODE • PART Z — INSPECTION 



S6.1 3.6.4 PRESSURE TESTING CARGO 
TANKS EQUIPPED WITH A 
HEATING SYSTEM 

If the cargo tank is equipped with a heating 
system, employing a medium such as, but not 
limited to, steam or hot water hydrostatically, 
pressure is as follows: 

a) The cargo tank must be tested at least once 
every five years; 

b) The test pressure for the heating system shall 
be at least to the maximum system design 
operating pressure; 

c) The test pressure shall be maintained for a 
least 5 minutes; and 

d) If the heating system employs flues for heat- 
ing the lading, the flues must be tested to 
ensure that the lading cannot leak into the 
flues or into the atmosphere. 



S6.1 3.6.5 EXCEPTIONS TO PRESSURE 
TESTING 

a) MC 330 and MC 331 cargo tanks are not 
required to be pressure tested that are in 
dedicated sodium metal service. 

b) Un-insulated cargo tanks, with a design 
pressure or MAWP of 15 psig or less, 
which can be externally visually inspected 
and a lining inspection at least once every 
five years, are not required to be pressure 
tested. 



S6.1 3.6.6 ACCEPTANCE CRITERIA 

a) The acceptance criteria for the hydrostatic 
or pneumatic pressure test of the heating 
system is based on the cargo tanks capabili- 
ties to successfully pass the pressure test, 
without showing evidence of permanent 
distortion or other evidence of weakness 



that might render the cargo tank unsafe for 
transportation service. 

b) If the cargo tank does not satisfy the require- 
ments for the pressure test of the heating 
system identified in (a) above, the cargo 
tank can not be returned to transportation 
service, unless: 

1) Cargo tanks with a heating system, 
which does not hold pressure, should 
remain inservice as an unheated cargo 
tank, if the heating system remains in 
place and is structurally sound and no 
lading may leak into the heating system; 
and 

2) The specification information for the 
heating system on the nameplate is 
changed to indicate that the cargo tank 
has no working heating system. 



S6.1 3.6.7 INSPECTION REPORT 

a) The Inspector shall prepare a written inspec- 
tion report that identifies the results of the 
pressure test and specifies the following: 

1) Manufacturer's serial number of the 
cargo tank; 

2) Name of the cargo tank manufacturer; 

3) DOT or MC specification number; 

4) MAWP of the cargo tank; 

5) Minimum thickness of the head and 
shell of the cargo tank; 

6) Identify whether the cargo tank is lined, 
insulated, or both; and 

7) Identify if the cargo tank is for special 
service, i.e., transport material cor- 
rosive to the cargo tank, dedicated 
service, etc. 



226 



NATIONAL HOARD INSPECTION CODE • PART 2 



INSPECTION 



b) The written inspection report shall provide 
for the following additional information: 

1) The type of test or inspection per- 
formed; 



2) Registration number of the facility or 
person performing the test; 

3) Continued qualification statement, 
such as: 



2) Date of the test or inspection (month 
and year). 

c) Listing of all items tested or inspected, in- 
cluding information about pressure relief 
valve: 

1) If the relief valve is removed, inspected 
and tested, or replaced; 

2) If applicable, type of the device; 

3) Set to discharge pressure at which the 
device will reseat; or 

4) If the device was reinstalled, repaired, 
or replaced. 

d) Information regarding the inspection of the 
upper coupler (fifth wheel) assembly, and 
when applicable: 

1) If the coupler assembly (fifth wheel) 
visually inspected in place; or 

2) If the coupler assembly (fifth wheel) 
removed for examination. 

e) Information regarding leakage, and type of 
pressure test (hydrostatic or pneumatic); 

f) The test pressure and holding time during 
the test; 

g) Location of defects found and the method 
of repair; 

h) Minimum thickness of the cargo tanks heads 
and shells, as specified in Table S6.1 3.1 -a 
or Table S6.13.1-b, as applicable; 

1 ) Name and address of the person per- 
forming the test; 



a. "cargo tank meets the requirements 
of DOT specification identified in 
this report;" 

b. "cargo tank fails to meet the re- 
quirements of the DOT specifica- 
tion identified in this report;" or 

c. DOT registration number of the 
registered inspector, and dated 
signature of the registered inspector 
and the cargo tank owner. 

The owner and the motor carrier shall 
retain a copy of the test and inspection 
reports until the next test or inspection of 
the same type is successfully completed. 
This requirement does not apply to a motor 
carrier leasing a cargo tank for fewer than 
30 days. 



S6.13.7 ADDITIONAL REQUIREMENTS 
FOR MC 330 AND MC 331 

CARGO TANKS 

After completion of the pressure test, each mo- 
tor carrier operating a Specification MC 330 
and MC331 cargo tank in anhydrous ammonia, 
liquefied petroleum gas, or any other service 
that is prone to stress corrosion cracking, shall 
make a written report containing the following 
information: 

a) Carrier's name, address of principal place 
of business, and telephone number; 

b) Complete identification plate data required 
by Specification MC 330 and MC 331 cargo 
tanks, including data required by the AS ME 
Boiler and Pressure Vessel Code; 

c) Carrier's equipment number; 



227 



NATIONAL BOARD INSPECTION CODE • PART 2 



INSPECTION 



cl) Statement indicating whether or not the 
cargo tank was stress relieved after fabrica- 
tion; 

e) Name and address of the person performing 
the test and date of the test; 

f) Statement of the nature and severity of any 
defects found. As a minimum, the informa- 
tion shall include: 



k) Upon written request to and with the ap- 
proval of the Field Administrator, Regional 
Service Center, and Federal Motor Car- 
rier Safety Administration for the region in 
which a motor carrier has its principal place 
of business, the carrier may maintain the 
reports at a regional or terminal office. 



S6.13.8 CERTIFICATES AND REPORTS 



1 ) Identification of the location of the de- 
fects detected, such as in weld, heat-af- 
fected zone, the liquid phase, the vapor 
phase, or the head to shell seam; or 

2) If no defects or damage was discovered, 
this also shall be reported. 

g) Statement indicating the methods employed 
to make repairs; that made the repairs; and 
the date the repairs were completed. If the 
cargo tank was stress relieved after the re- 
pairs were completed, whether full or local 
stress relieving was performed; 

h) Statement of the disposition of the cargo 
tank, such as: 

1 ) "cargo tank scrapped"; or 

2) "cargo tank returned to service." 

i) Statement whether or not the cargo tank is 
used in anhydrous ammonia service that is 
subject to stress corrosion cracking. If the 
cargo tank had been used in anhydrous 
ammonia service since the last report, the 
owner has to provide a statement in the 
report indicating whether each shipment 
of ammonia was certified by its shipper as 
containing at least 0.2% water by weight; 

j) A copy of the written inspection report must 
be retained by the carrier at its principal 
place of business during the period the 
cargo tank is in the carrier's service and for 
one year thereafter. 



a) Each person offering a DOT specification 
cargo tank for sale or lease must provide the 
purchaser or lessee with the following: 

1 ) A copy of the cargo tank certificate of 
compliance; 

2) If applicable, a copy of the record of 
repair, modification, stretching, or re- 
barrelling; 

3) The most recent inspection and test 
reports. 

b) Copies of the documents and reports identi- 
fied in (a) above must be provided to the 
lessee if the cargo tank is leased for more 
than 30 days. 



S6.13.9 LEAKAGE TEST 

When leakage testing is required by Table 
S6.13.4 of this supplement, the test shall in- 
clude testing the product piping with all valves 
and accessories in place and operative, except 
that any venting devices set to discharge at less 
than the leakage test pressure must be removed 
or rendered inoperative during the test. The 
leakage test shall include: 

a) All internal or external self-closing stop 
valves must be tested for leakage; 

b) Each cargo tank of a multi-cargo tank motor 
vehicle must be tested with the adjacent 
cargo tanks empty and at atmospheric pres- 
sure; 



22S 



NATIDNAL BOARD INSPECTION CODE 



PART Z 



INSPECTION 



c) The leakage test shall be maintained for a 
minimum of five minutes; 

d) Cargo tanks in liquefied compressed gas 
service shall be: 

1) Inspected externally for leaks during 
the leakage test; 

2) Suitable safeguards must be provided 
to protect personnel should a failure 
occur, as follows: 

a. Cargo tanks may be leakage tested 
with the hazardous material in the 
cargo tank during the test; 

b. The leakage test pressure shall not 
be less than 80% of the MAWP 
marked on the specification plate, 
unless the cargo tank has a MAWP 
of 690 kPa (60 psig) or more, in 
which case it should be leak tested 
at its maximum normal operating 
pressure provided it is in dedicated 
service or services; 

c. MC 330 or MC 331 cargo tanks in 
dedicated liquefied petroleum gas 
service may be leakage tested at not 
less than 414 kPa (60 psig); 

d. An operator of aMC330or MC331 
cargo tank and a non-specification 
cargo tank equipped with a meter 
should check leak tightness of the 
internal self-closing stop valve by 
conducting a meter creep test; 

e. A non-specification cargo tank is 
a cargo tank that conforms and is 
marked in conformance with the 
edition of the ASME Code in effect 
when the cargo tank was fabricated 
and should be used for the transpor- 
tation of liquefied petroleum gas, 
provided the cargo tanks satisfies 
the following: 



1. The cargo tank has a mini- 
mum design pressure no 
lower than 250 psig; 

2. The cargo tank has a water 
capacity of 13,247.5 I (3500 
gallons) or less. 

3) The cargo tank has been manufactured 
in accordance with the ASME Code 
prior to January 1 , 1 981 . This require- 
ment requires the cargo tank to be 
stamped with the ASME Code Symbol 
Stamp and documented on an ASME 
Manufacturer's Data Report; 

4) The cargo tank shall conform to the 
applicable provisions of NFPA 58, 
except if NFPA is inconsistent with the 
requirements of Parts 178 and 180 of 
Title 49; 

5) The cargo tank shall be leakage tested 
in accordance with Table S6.1 3.4; 

6) MC 330 and MC 331 cargo tanks in 
dedicated service for anhydrous am- 
monia may be leakage tested at not less 
than 414 kPa (60 psig); 

7) Non-specification cargo tanks must be 
leakage tested at pressure of not less 
than 16.6 kPa (2.4 psig), if the cargo 
tanks complies with one of the follow- 
ing: 

a. For the transport of petroleum prod- 
ucts that have a liquid capacity of 
13,250 I (3500 gal); 

b. Permanently secured non-bulk 
tanks to a motor vehicle and pro- 
tected against leakage or damage 
in the event of turnover, having a 
liquid capacity of less than 450 I 
(1 1 9 gal), used for transportation 
of a flammable liquid petroleum 
product. 



229 



NATIONAL BOARD INSPECTION GODE • PART 2 



INSPECTION 



8) The cargo tank is used to transport pe- 
troleum distillate fuels that are equipped 
with a vapor collection equipment and 
should be leakage tested in accordance 
with the Environmental Protection 
Agency's "Model 27-Determination of 
Vapor Tightness of Gasoline Delivery 
Tank Using Pressure- Vacuum Test", as 
follows: 

a. The test method and procedures 
and maximum allowable pressure 
and vacuum changes are in 40 CFR 
63.425(e)(1); 

b. The hydrostatic test alternative, 
using liquid in Environmental 
Protection Agency's "Method 27- 
Determination of Vapor Tightness 
of Gasoline Delivery Tank Using 
Pressure-Vacuum Test" should not 
be used to satisfy the leak testing 
requirements of this section. The 
test shall be conducted using air; 

c. Cargo tanks equipped with vapor 
collection equipment should be 
leakage tested in accordance with 
(8)(b) above. 

9) Cargo tanks that fail to retain leakage 
test pressure shall not be returned to 
service as a specification cargo tank, 
unless all sources of leakage are proper- 
ly repaired prior to returning the cargo 
tank to hazardous material service. 

1 0) It is required that after July 1 , 2000, that 
the Registered Inspector that performs 
inspection on MC 330 and MC 331 
cargo tanks inspect the delivery hose 
assembly and the piping system of the 
cargo tank under leakage test pressure 
utilizing the rejection criteria for cargo 
tanks unloading liquefied compressed 
gas. It should be noted that an operator 
should remove and replace damaged 
sections or correct defects discovered 
as provided in S6. 13.10. If any of the 
following is discovered, it is cause for 
rejection: 



a. No operator shall use a delivery 
hose assembly for liquefied com- 
pressed gas if it is determined that 
any of the following conditions 
exist: 

1 . Damage to the hose cover that 
exposes the reinforcement; 

2. If the wire braid reinforcement 
is kinked or flattened so as to 
permanently deform the wire 
braid; 

3. Soft spots when the hose is 
not under pressure, or any 
loose outer covering on the 
hose; 

4. Damaged, slipping, or exces- 
sively worn hose couplings; 

5. Loose or missing bolts or 
fastenings on the bolted hose 
coupling assembly. 

b. No operator can use a cargo tank 
with a piping system for unloading 
liquefied compressed gasses if any 
of the following conditions exist: 

1 . Any external leaks identifiable 
without the use of instruments; 

2. Bolting that is loose, missing, 
or severely corroded; 

3. Manual stop valves that will 
not actuate; 

4. Rubber hose flexible connec- 
tors with any of the following 
conditions: 

aa. damage to the hose cover 
that exposes the reinforce- 
ment; 

bb. if the wire braid rein- 
forcement is kinked or 
flattened so as to perma- 
nently deform the wire 
braid; 



23D 



NATIONAL BOARD INSPECTION CODE • PART 2 



INSPECTION 



cc. soft spots when the hose 
is under pressure, or any 
loose outer covering on 
the hose; 

dd. damaged, slipping, or 
excessively worn hose 
couplings; 

ee. loose or missing bolts or 
fastenings on the bolted 
hose coupling assembly; 

ff. Stainless steel flexible 
connectors with damaged 
reinforcement braid; 

gg. Internal self-closing stop 
valves that fail to close 
or that permit leakage 
through the valve detect- 
able without the use of 
instruments; 

hh. Pipes or joints that are 
severely corroded. 



S6.13.10 NEW OR REPLACED DELIVERY 
HOSE ASSEMBLIES 

The operator shall repair hose assemblies and 
place the cargo tank back inservice if retested 
successfully in accordance with the following: 

a) The new and/or replaced hose assembly is 
tested at a minimum of 120% of the hose's 
MAWP; 

b) The operator shall visually examine the 
delivery hose assembly while its under 
pressure; 

c) If the test is successful, the operator shall 
assure that the delivery hose assembly is 
permanently marked with the month and 
year of the test; 

d) It should be noted that after July 1 , 2000, 
the operator shall complete a record docu- 



menting the test and inspection, which shall 
include the following: 

1 ) The date and signature of the Inspector 
that performed the inspection; 

2) The owner of the hose assembly; 

3) The hose identification number; 

4) The date of the original delivery of the 
hose assembly and tests; 

5) Notes of any defects observed; 

6) Any repairs that may have been made; 
and 

7) Identification in the written report that 
the delivery hose assembly passed or 
failed the tests and inspections. 



S6.1 3.10.1 THICKNESS TESTING 

a) Thickness testing of the head and shell of 
unlined cargo tanks used for the transporta- 
tion of materials corrosive to the cargo tank 
shall be measured at least once every two 
years. 

b) Cargo tanks measuring less than the sum of 
the minimum prescribed thickness in Tables 
S6.1 3.1 -a or S6.1 3.1 -b, as applicable, plus 
one-fifth of the original corrosion allow- 
ance shall be tested annually. 



S6.13.10.2 TESTING CRITERIA 

The testing criterion that shall be used for these 
requirements are as follows: 

a) The measuring device shall be capable of 
accurately measuring thickness to within ± 
0.002 of an inch; 



23 1 



NATIONAL BOARD INSPECTION CODE • PART 2 



INSPECTION 



b) The individuals performing thickness test- 
ing shall be trained in the proper use of the 
thickness testing device used in accordance 
with the testing device manufacturer's in- 
structions; 

c) Thickness testing shall be performed in the 
following areas, as a minimum: 

1) Areas of the tank shell and heads, in- 
cluding around any piping that retains 
lading; 

2) Areas of high shell stress, such as the 
bottom center of the cargo tank; 

3) Areas near openings; 

4) Areas around weld joints; 

5) Areas around shell reinforcements; 

6) Areas around appurtenance attach- 
ments; 

7) Areas near the upper coupler (fifth 
wheel) assembly attachments; 

8) Areas near suspension system attach- 
ments and connecting structures; 

9) Known thin areas in the tank shell and 
nominal liquid level lines; and 

1 0) Connecting structures joining multiple 
cargo tanks of carbon steel in a self- 
supporting cargo tank motor vehicle. 



S6.13.10.3 THICKNESS REQUIREMENTS 

a) The minimum thickness for MC 300, MC 
301 , MC 302, MC 303, MC 304, MC 305, 
MC 306, MC 307, MC 310, and MC 312 
cargo tanks are determined based on the 
definition of minimum thickness defined in 
CFR, Title 49, Part 1 78.320(a). 



b) TablesS6.13.1-aandS6.13.1-b identify the 
"Inservice Minimum Thickness" values to 
determine the minimum thickness for the 
referenced cargo tank. 

c) The tables are divided into three columns. 
The column headed "Minimum Manufac- 
tured Thickness" indicates the minimum 
values required for new construction if 
DOT 400 series cargo tanks. 

d) The "Inservice Minimum Thicknesses" 
for cargo tanks specified in (a) above are 
based on 90% of the manufactured thick- 
ness specified in the DOT Specification, 
rounded off to three places. 



S6.13.11 CARGO TANKS THAT NO 

LONGER CONFORM TO THE 
MINIMUM THICKNESS 
REQUIREMENTS IN TABLES 
S6.13.1-aANDS6.13.1-b 

If a cargo tank does not conform to the mini- 
mum thickness requirements inTablesS6.13.1- 
a and S6.1 3.1 -b for the design as manufactured, 
the cargo tank should be used at a reduced 
maximum weight of lading or reduced MAWP, 
or combinations thereof, provided the follow- 
ing is met: 

a) The cargo tank's design and thickness are 
appropriate for the reduced loadings condi- 
tions as follows: 

1) The cargo tank's design and thickness 
for the appropriate reduced loading 
shall be certified by a Design Certifying 
Engineer; 

2) A revised manufacturer's certificate 
shall be issued; and 

3) The cargo tanks motor vehicle's name- 
plate shall reflect the revised service 
limits. 

b) It is required if a cargo tank no longer 
conforms with the minimum thickness 



232 



NATIONAL BOARD INSPECTION CODE • PART 2 — INSPECTION 



requirements prescribed in the specifica- 
tion, that the cargo tank cannot be returned 
to hazardous material service. The cargo 
tank's specification plate shall be removed, 
obliterated, or covered in a secure manner. 
The inspector shall require that the cargo 
tank is calculated to identify the thickness 
of the material as required in S6. 13. 10.1 
and S6.1 3.1 0.2 of this section. 

c) MC cargo tanks constructed prior to Oc- 
tober 1, 2003, require that the minimum 
thickness, minus the corrosion allowance 
as provided on the Manufacturer's Data 
Report. 

d) MC cargo tanks constructed after October 
1, 2003, require that the minimum thick- 
ness will be the value indicated on the 
specification plate of the cargo tank. If no 
corrosion allowance is indicated on the 
Manufacturer's Data Report, then the thick- 
ness of the cargo tank shal I be the thickness 
of the material of construction indicated on 
the Manufacturer's Data Report, with no 
corrosion allowance. 



b) 



Boiler and Pressure Vessel Code that are not 
stamped with the "U" Code Symbol Stamp 
must be constructed out of ASTM materi- 
als permitted in Part 1 78.345-2 of Title 49. 
These materials are as follows: 

1) ASTM A 569, 

2) ASTM A 570, 

3) ASTM A 572, 

4) ASTM A 607, 

5) ASTM A 622, 

6) ASTM A 656, and 

7) ASTM A 71 5. 

Aluminum alloys suitable for fusion weld- 
ing and conforming with the O, H 32, or 
H 34 temper of one of the following ASTM 
Specifications may be used for cargo tanks 
constructed in accordance with the ASME 
Boiler and Pressure Vessel Code: 



S6.13.11.1 MINIMUM THICKNESS FOR 
400 SERIES CARGO TANKS 

400 series cargo tanks are required to satisfy the 
minimum thickness requirements as established 
in Part 1 78.320(a) of Title 49 for DOT 406 cargo 
tanks, Part 178.347.2 of Title 49 for DOT 407 
cargo tanks and Part 178.348.2 of Title 49 for 
DOT 412 cargo tanks. 



S6.1 3.1 1 .2 DOT 406 CARGO TANKS 

a) It is required that all head, shell, bulkhead, 
and baffle materials used in the construc- 
tion of DOT 406 cargo tanks satisfy Parts A 
and B of Section II of the ASME Boiler and 
Pressure Vessel Code, except that the fol- 
lowing materials are authorized for cargo 
tanks constructed in accordance with ASME 



c) 



1) ASTM B 209, A 

2) ASTM B 209, A 

3) ASTM B 209, A 

4) ASTM B 209, A 

5) ASTM B 209, A 

6) ASTM B 209, A 



loy 5052, 
loy 5086, 
loy 51 54, 
loy 5254, 
loy 5454, and 
loy 5652. 



All heads, bulkheads, and baffles must be of 
O temper (annealed) or stronger temper. All 
shell material shall be of H 32, or H 34 tem- 
per, except that the lower ultimate strength 
temper should be used if the minimum 
shell thickness in the tables are increased in 
proportion to the lesser ultimate strength. 



d) Table S6.1 3.11 .2-a specifies the mini- 
mum thickness requirements for heads or 



233 



NATIDNAL BOARD INSPECTION CODE • PART 2 — INSPECTION 



Table S6.1 3.1 1.2 -a 
Minimum Thickness for Heads 



Materials 


Volume capacity i 


n gallons per inch of length (liter 


>er mm of length) 




14 (0.2 Dor less 


Over 14 to 23 (0.21 to 0.36) 


Over 23 ;0.36* 


MS HSLA 
SS 


AL 


MS 


HSLA 
SS 


AL 


MS 


HSLA 
SS 


AL 


Thickness, 

in. (mm) 


.100 

(2.54) 


.100 

(2.54; 


.160 
(4.06) 


.115 
(2.92) 


.155 
(3.94) 


.173 
(4.39) 


.129 
(3.28) 


.129 
(3.28) 


.187 
14.75) 



Table S6.1 3.1 1.2-b 

Minimum Thickness for Shells, in. (mm) 



Cargo tank motor vehicle rated capacity in gallons (liters) ! MS SS/HSLA AL 


More than to at least 4,500 (0 to 1 7,000) 


0.100(2.54) 


0.100(2.54) 


0.151 (3.84) 


More than 4,500 to at least 8,000 (1 7,000 to 30,300) 


0.115(2.92) 


0.100(2.54) 


0.160(4.06) 


More than 8,000 to at least 14,000 (30,300 to 53,000) 


0.129(3.28) 


0.129(3.28) 


0.173 (4.39) 


More than 14,000(53,000) 


0.143 (3.63) 


0.143 (3.63) 


0.187(4.75) 


Note: The maximum distance between bulkhead, baffles, or ring stiffeners shall not exceed 60 inches (1,525 mm) 



bulkheads and baffles when used as tank 
reinforcement that is based on the volume 
capacity in gallons per I per mm (inch) of 
length for MC 406 cargo tanks constructed 
out of Mild Steel (MS), High Strength Low 
Alloy Steel (HSLA), Austenitic Stainless 
Steel (SS), or Aluminum (AL). 

Table S6.1 3.1 1 .2-b specifies the minimum 
thickness requirements for shell based on 
the cargo tank motor vehicle rated ca- 
pacity in gallons when the cargo tank is 
constructed out of Mild Steel (MS), High 
Strength Low Alloy Steel (HSLA), Austenitic 
Stainless Steel (SS), or Aluminum (AL). The 
thickness requirements in these tables are 
specified in decimal of a mm (inch) after 
forming. 



S6.1 3.1 1 .3 DOT 407 CARGO TANKS 

a) It is required that the type of materials used 
for DOT 407 cargo tanks, depending on the 
type of media being transferred be either 
Mild Steel (MS), High Strength Low Alloy 



Steel (HSLA), Austenitic Stainless Steel (SS), 
or Aluminum. 

b) The minimum required thickness of materi- 
als specified in Table S6. 13.1 1 .3-afor DOT 
407 cargo tanks, when the minimum thick- 
ness requirements are based on the volume 
capacity in Liters (I per sq mm) (gallons) per 
square mm (inch) for the cargo tank's heads, 
or bulkheads and baffles, when these items 
are used for reinforcement purposes. All 
thicknesses are expressed in decimals of a 
mm (inch) after forming. 

c) The minimum required thickness of materi- 
als specified inTable S6.1 3.1 1.3-bfor DOT 
407 cargo tanks, when the minimum thick- 
ness requirements are based on the volume 
capacity in Liters (I per sq. mm) (gallons) per 
square mm (in.ch) for the cargo tank shell. 
All thicknesses are expressed in decimals 
of a mm (inch) after forming. 



234 



NATIONAL BOARD INSPECTION CODE • PART Z 



INSPECTION 



Table S6.1 3.1 1.3-a 

Minimum Thickness for Heads (DOT 407), in. (mm) 



Volume capacity 
in gal./sq. in. 
(l/sq. mm) 


10 (0.122) 
or less 


Over 1 
to 14 

(0.122 
to 0.171) 


Over 1 4 
to 18 

(0.171 
to 0.22) 


Over 1 8 
to 22 
(0.22 
to 0.268) 


Over 22 
to 26 
(0.268 
to 0.317) 


Over 26 
to 30 

(0.31 7 
to 0.365) 


Over 30 
(0.365) 


Thickness (MS) 


0.10.0 

(2.54) 


0.100 

(2.54) 


0.115 
(2.92) 


0.129 
(3.28) 


0.129 
(3.28) 


0.143 
(3.63) 


0.156 
(3.96) 


Thickness 
(HSLA) 


0.100 

(2.54) 


0.100 

(2.54) 


0.115 
(2.92) 


0.129 

(3.28) 


0.129 

(3.28) 


0.143 
(3.63) 


0.156 
(3.96) 


Thickness (SS) 


o.too 

(2.54) 


0.100 

(2.54) 


0.115 

(2.92) 


0.129 
(3.28) 


0.129 
(3.28) 


0.143 
(3.63) 


0.156 
(3.96) 


Thickness (A) 


0.160 
(4.06) 


0.160 

(4.06) 


0.173 
(4.39) 


0.187 

(4.75) 


0.194 
(4.92) 


0.216 

(5.49) 


0.237 
(6.02) 



TableS6.13.11.3-b 

Minimum Thickness for Shells (DOT 407), in. (mm) 



Volume capacity 
in gal./sq. in. 

(l/sq. mm) 


10(0.122) 
or less 


Over 10 
to 14 
(0.122 
to 0.171) 


Over 1 4 
to 18 
(0.171 
to 0.22) 


Over 1 8 
to 22 
(0.22 
to 0.268) 


Over 22 
to 26 
(0.268 
to 0.317) 


Over 26 
to 30 

(0.317 
to 0.365) 


Over 30 

(0.365) 


Thickness (MS) 


0.100 

(2.54) 


0.100 

(2.54) 


0.115 

(2.92) 


0.129 
(3.28) 


0.129 
(3.28) 


0.143 
(3.63) 


0.156 
(3.96) 


Thickness 

(HSLA) 


0.100 

(2.54) 


0.100 

(2.54) 


0.115 

(2.92) 


0.129 

(3.28) 


0.129 
(3.28) 


0.143 
(3.63) 


0.156 
(3.96) 


Thickness (SS) 


0.100 

(2.54) 


0.100 

(2.54) 


0.115 
(2.92) 


0.129 
(3.28) 


0.129 
(3.28) 


0.143 
(3.63) 


0.156 
(3.96) 


Thickness (A) 


0.151 
(3.84) 


0.151 
(3.84) 


0.160 

(4.06) 


0.173 
(4.39) 


0.194 

(4.92) 


0.216 

(5.49) 


0.237 
(6.02) 



S6.1 3.1 1 .4 DOT 41 2 CARGO TANKS 

a) It is required that the type of materials used 
for DOT cargo tanks, depending on the type 
of media being transferred be either Mild 
Steel (MS), High Strength Low Alloy Steel 
(HSLA), Austenitic Stainless Steel (SS), or 
Aluminum. 

b) The minimum required thickness of materi- 
als specified in Table S6. 13.1 1 .4-afor DOT 
41 2 cargo tanks, when the minimum thick- 
ness requirements are based on the volume 
capacity in liters (I per sq mm) (gallons) per 
square mm (inch) for cargo tanks head, or 
bulkheads and baffles, when these items 



are used for reinforcement purposes. All 
thicknesses are expressed in decimals of 
mm (inch) after forming. 

The minimum required thickness of materi- 
als specified inTableS6.13.11.4-bfor DOT 
41 2 cargo tanks, when the minimum thick- 
ness requirements are based on the volume 
capacity in liters (I per sq mm) (gallons) per 
mm (square in) for the cargo tank's shell. 
All thicknesses are expressed in decimals 
of mm (inch) after forming. 



235 



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NATIONAL BOARD INSPECTION CODE • PART 2 



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Minimum Thickness for Heads (D 


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238 



NATIDNAL BDARD INSPECTION CODE • PART 2 



INSPECTION 



S6.14 INSPECTION AND TESTS OF 

PORTABLE TANKS 

a) For hazardous material ladings, all por- 
table tanks shall be inspected and tested 
at frequencies specified inTableS6.14.The 
inspection and tests shall include visual 
inspection of external and internal surfaces, 
leak test, pressure test, thickness measure- 
ments, and lining test. It should be noted 
that the information in S6.1 4 is a summary 
of CFR Title 49, Part 180.601 through Part 
180.605. The user is responsible for full 
compliance with the requirements in 
CFR Title 49, Part 180.601 through Part 
180.605. 

b) All portable tanks shall be visually inspected 
(internal, unless otherwise noted, and exter- 
nally) for any condition that might render 
the portable tank unsafe for transportation 
service. The inspection shall include: 

1) Inspection of the shell for pitting, cor- 
rosion or abrasions, dents, distortions 
or abrasions, defects in welds, or any 
other conditions, including leakage; 



2) Inspection of the piping, valves, and 
gaskets for corroded areas, defects, and 
other conditions, including leakage 
that may be unsafe during filling and 
discharge or transportation. 

In addition to the required frequencies 
established in Table S6.14, it is required 
that portable tanks be inspected and tested 
when any of the following occurs: 

1) The portable tank has been in an ac- 
cident and has been damaged to an 
extent that may adversely affect the 
portable tank's ability to retain hazard- 
ous materials; 

2) The portable tank has been out of haz- 
ardous material transportation service 
for a period of one year or more; 

3) The portable tank has been modified 
from its original design specification; 
and 

4) The portable tank is in an unsafe oper- 
ating condition based on the existence 



TabIeS6.14 
Inspection Intervals 



... . ,._.., i intermediate Periodic 
.„ . Periodic Inspection and Test' , .. . T ., 
Specification r Inspection and Test 2 


IM or UN Portable Tanks 
once placed in service 


5 years 


2-1/2 years 


DOT 51 Portable Tanks 


5 years 


— 


DOT 56 or DOT 57 Portable Tanks 
(The first periodic inspection and 
test is required 4 years after being 
placed into service and each 2-1/2 
years thereafter.) 


2-1/2 years 


— 


DOT 60 Portable Tanks 
(The first periodic inspection and 
test is required 4 years after being 
placed into service and then per 
the schedule to the right.) 


For the first 12 years 

of service 2 years 


After 12 years 

of service yearly 


1 Retesting is not required on a rubber lined tank, except before relining. 

- For IM and UN Portable Tanks, periodic inspection and test shall include at least an internal and external of 

the portable tank and fittings, taking into account the hazardous material intended to be transported. 



239 



NATIONAL BDARD INSPECTION CODE • PART 2 — INSPECTION 



of observed damage, leaks, or missing 
safety devices, etc. 



empt from the internal inspection require- 
ments, but shall be externally inspected. 



S6.14.1 PERIODIC INSPECTION 
AND TEST 

Portable tanks shall be tested and inspected in 
accordance with the frequency set forth in Table 
S6.14 and the procedures set forth in S6.14.3 
through S6. 14.6.4. 



S6.14.2 INTERMEDIATE PERIODIC 
INSPECTION AND TEST 

a) Intermediate periodic inspections and test- 
ing shall be performed in accordance with 
Table S6.14. The intermediate periodic 
inspection and testing shall include: 

1 ) An external and an internal inspection 
of the portable tank and its fittings tak- 
ing into account the hazardous materi- 
als being transported; 

2) A leakage test of the transport tank; 
and 

3) A test for satisfactory operation of all 
service equipment. 

b) When inspecting portable tanks equipped 
with sheathing and thermal insulation, etc., 
the insulation need only be removed to the 
extent required for a reliable appraisal of 
the condition of the portable tank 

c) For portable tanks intended for the trans- 
portation of a single hazardous material, 
the internal inspection may be waived if 
the portable tank is subjected to a leakage 
test that is performed in accordance with 
S6.14.3 of this section prior to each filling. 

d) Portable tanks used for dedicated transpor- 
tation of refrigerated liquefied gases that are 
not fitted with inspection openings are ex- 



S6.14.3 INTERNAL AND EXTERNAL 
INSPECTIONS 

All portable tanks that are subject to five year 
periodic inspection and testing (pressure test) 
are required to be inspected, both internally, 
unless exempt, and externally. The internal and 
external inspection shall include: 

a) Sheathing, thermal insulation, etc. The 
sheathing and thermal insulation need 
only be removed to the extent required for 
reliable appraisal of the condition of the 
portable tank. 

b) Except for DOT Specification 56 and 57 
portable tanks, all re-closing pressure relief 
devices must be removed from the tank and 
tested separately unless they can be tested 
while installed on the portable tank. 

c) For portable tanks where the shell and 
equipment have been pressure tested sepa- 
rately after assembly, the portable tank shall 
be subjected to a leakage test and effec- 
tively tested and inspected for corrosion. 

d) Portable tanks used for the transportation 
of refrigerated, liquefied gases are exempt 
from the internal inspection and the hydro- 
static test or other pressure test during the 
5 year periodic inspection if the portable 
tank was originally tested to a minimum test 
pressure of 1 .3 times the design pressure 
using inert gas and provided that: 

1 ) The portable tank and its appurtenances 
were constructed to ASME Section XII, 
or ASME Section VIII, Division 1; the 
portable tank shall be inspected in ac- 
cordance with the applicable require- 
ments of this Code. 



Z4D 



NATIONAL BOARD INSPECTION CDDE • PART 2 



INSPECTION 



2) Portable tanks shall be either hydrostati- 
cally or pneumatically tested with the 
formula 1 .5 x design pressure + static 
head + 1 4.7 psi (1 01 kPa), if the tank is 
designed for external pressure. 

3) The portable tank shall be subjected to 
either a hydrostatic or pneumatic test at 
a test pressure of 1 .5 x the sum of the 
design pressure + the static head of lad- 
ing + 14.7 psi (1 01 kPa), if subjected to 
external vacuum. If the portable tank is 
constructed in accordance with ASME 
Section XII or Part UHT of ASME Sec- 
tion VIII, Div. 1, the test pressure shall 
be twice the design pressure. 

4) A pneumatic test may be used in lieu 
of a hydrostatic test if the following 
conditions are met: 

a. The owner-user has taken necessary 
precautions to ensure the safety of 
the inspection and test personnel; 

b. The pneumatic test pressure shall 
be reached gradually by increas- 
ing the test pressure to one-half of 
the test pressure. Once this pres- 
sure is reached, the test pressure 
will be increased in increments 
of approximately one-tenth of the 
test pressure until the required test 
pressure is reached; and 

c. When the test pressure is reached, 
the test pressure shall be reduced 
to at least four-fifths of the test pres- 
sure and held for a sufficient time 
to permit inspection of the portable 
tank. 



S6.14.4 EXCEPTIONAL INSPECTION 
AND TEST 

a) Exceptional inspection and test is neces- 
sary when a portable tank shows evidence 



of damage, corroded areas, or leakage, or 
other conditions that indicate a deficiency 
that could affect the integrity of the portable 
tank. 

b) The extent of the exceptional inspection 
and test shall depend on the amount of de- 
terioration of the portable tank. The excep- 
tional inspection and test shall include the 
requirements of S6.1 4.3 of this section. 

c) Pressure relief devices do not need to be 
included in this test unless there is reason to 
believe the relief device has been affected 
by damage or deterioration. 



S6.14.5 INTERNAL AND EXTERNAL 
INSPECTION PROCEDURE 

An internal and external inspection, when 
required, shall be performed by the owner- 
user. The inspection shall be conducted by the 
Inspector. This individual shall ensure that the 
portable tank is safe for continued transporta- 
tion service. The Inspector shall evaluate the re- 
sults of the inspection and report the applicable 
findings. The inspection shall include: 

a) Inspection of the shell for pitting, corrosion 
or abrasions, dents, distortions, defects in 
welds, or any other conditions, including 
leakage; 

b) Inspection of the piping, valves, and gas- 
kets for corroded areas, defects, and other 
conditions, including leakage that might 
make the portable tank unsafe for filling, 
discharge, or transportation; 

c) The tightening devices for manhole covers 
are operative, and there is no leakage at the 
manhole cover or gasket; 

d) Missing or loose bolts or nuts on any flanged 
connections including piping flanges, pres- 
sure relief device connections, or blank 
flanges. If any bolts are loose or missing, 
these shall be tightened or replaced; 



24 i 



NATIDNAL BOARD INSPECTION CODE • PART 2 



INSPECTION 



e) All emergency devices and valves to 
ensure that they are free from corrosion, 
distortion, and any damage or defects that 
could prevent the devices from operating 
as designed; 

f) All remote closures and self-closing stop 
valves shall be operated to demonstrate 
their proper operation; 

g) The required markings on the portable tanks 
shall be legible and in accordance with the 
applicable requirements of CFR Title 49, 
Part 1 78.3, and Part 1 80.605; and 

h) The framework, supports, and the arrange- 
ments for lifting the portable tank to ensure 
that they are in a satisfactory condition. 



S6.14.6 PRESSURE TESTS PROCEDURES 
FOR SPECIFICATION 51, 57, 60, 

IM OR UN PORTABLE TANKS 

This section provides the requirements for 
pressure test procedures for Specification 51, 
57, 60, IM or UN Portable Tanks as provided 
in CFR Title 49, Part 180.605(h). Pressure test 
requirements for Specification 51, 57, 60, IM 
and UN Portable Tanks are identified in Table 
S6.1 3.6 of this subsection. 



S6.1 4.6.1 SPECIFICATION 57 PORTABLE 
TANKS 

a) Specification 57 portable tanks shall be 
leak tested by a minimum sustained air 
pressure of at least 3 psig applied to the 
entire tank. 



Table S6.1 4.6 

Pressure Testing Requirements 



Specification Leak Test Hydrostatic 


Pneumatic 


Test Media 


Minimum Test Pressure 


51 and 56 j — X 


X 


Liquid or Air 


2 psi or at least 1-1/2 
times the design pressure, : 
whichever is greater 


51 and 56 used for 
transport refriger- 
ated liquefied gas 


X 


X 


X 


Liquid or Air 


90% of the Maximum 
Allowable Working 
Pressure 


51 and 56 for the 
transport of all other 
materials 


: X 


X 


Liquid or Air 


25% of the Maximum 
Allowable Working 
Pressure 


57 


X 


— 


— 


— 


3 psi to the entire tank 


60 


— 


— 


— 


Water or 
other similar 
liquid 


60 psig 


UN nonrefrigerated 
gases 


— 


— 


— 


Water 


1 30% of Maximum 
Allowable Working 
Pressure 


UN refrigerated : — i X 
gases 


X 


Water or Air 


1.3 times design pressure 


IM refrigerated or 
nonrefrigerated 
liquefied gases 




X 


X 


Water or Air 


1 50% of the Maximum 
Allowable Working 
Pressure 



242 



NATIONAL BOARD INSPECTION CDDE • PART 2 — INSPECTION 



b) During each air pressure test, the entire 
surface of all joints, whether welded or 
threaded shall be coated with or immersed 
in a solution of soap and water, heavy oil, 
or other material suitable for the purpose 
of detecting leaks. 

c) The test pressure shall be held for a mini- 
mum of five minutes plus any additional 
time required to examine all portions of 
the portable tank. 

d) During the air test, the pressure relief de- 
vice may be removed or left in place. If 
the relief device is left in place during the 
test, the device's discharge opening shall 
be plugged. 

e) All closure fittings must be in place during 
the pressure test. 

f) If the portable tank is lagged or insulated, 
the lagging or insulation does not have to 
be removed if it is possible to maintain 
the required test pressure at a constant 
temperature with the portable tank discon- 
nected from the source of pressure. 



S6.14.6.2 SPECIFICATION 51 OR 56 

PORTABLE TANKS 

a) Specification 51 or 56 portable tanks shall 
be tested using either air or liquid. The 
minimum test pressure shall be at least 2 
psig or at least one and one-half times the 
maximum allowable working pressure (or 
re-rated pressure) of the portable tank. The 
greater test pressure shall be used. 

b) The leak testing of all refrigerated liquefied 
gas tanks shall be performed at 90% of the 
maximum allowable working pressure of 
the portable tank. 

c) Leak testing for all other portable tanks shall 
be at a test pressure of at least 25% of the 
maximum allowable working pressure of 
the portable tank. 



d) If the portable tank is hydrostatical ly tested, 
the entire surface of the portable tank shall 
be inspected for leaks. This includes all 
welded joints and threaded connections. 
The requirements below shall be followed 
for hydrostatic testing: 

1) The hydrostatic test pressure shall be 
held for a minimum of 5 minutes plus 
any additional time required to com- 
plete the inspection; 

2) The pressure relief device should be 
removed or left in place during the hy- 
drostatic test. If the relief device is left 
in place during the test, the device shall 
be isolated to avoid the relief device 
from discharging in accordance with 
the device manufacturer's recommen- 
dations; 

3) It is required for DOT 51 specification 
tanks that the relief valve be removed 
during the pressure test; and 

4) All closure fittings shall remain in place 
during the hydrostatic test. 

e) If the portable tank is pressure tested by air, 
during the test all surfaces of welded joints 
and thread connections of the portable tank 
shall be inspected for leaks and the follow- 
ing procedure shall be followed: 

1 ) All welded joints and threaded connec- 
tions shall be coated with or immersed 
in a solution of soap and water, or 
heavy oil or other material suitable for 
the purpose of detecting leaks; 

2) The air test pressure shall be held for a 
minimum of five minutes. This time pe- 
riod should be increased if so required 
by the Inspector; 

3) The pressure relief device should be 
removed or left in place during the 
air test. If the relief device is left in 
place during the test, the device shall 



243 



NATIONAL BOARD INSPECTION CDDE • PART Z 



INSPECTION 



be isolated to avoid the pressure relief 
device from discharging in accordance 
with the device manufacturer's recom- 
mendations; 



4) For Specification 5 1 portable tanks, the 
relief device shall be 
the pressure test; and 



relief device shall be removed during 



5) All closure fittings shall remain in place 
during the air test. 

If the portable tank is lagged or insulated 
and the pressure test performed is either 
hydrostatic or pneumatic, it is not neces- 
sary to remove the lagging or insulation for 
pressure testing provided the decay in test 
pressure can be measured at a constant 
temperature while the portable tank is dis- 
connected from the source of pressure. 



S6.1 4.6.3 SPECIFICATION 60 PORTABLE 

TANKS 

Specification 60 portable tanks shall be tested 
by completely filling the portable tank with 
water or other liquid having a similar viscosity. 
The test procedure shall include: 

a) The temperature of the liquid shall not 
exceed 37.7°C (1 00°F) during the test; 

b) The test pressure applied shall be at least 
60 psig; 

c) The test pressure shall be maintained for a 
minimum of 1 minutes. This time period may 
be increased if required by the Inspector; 

d) During the 1 0-minute time period, the por- 
table tank shall be capable of maintaining the 
test pressure with no evidence of leakage; 

e) All closures shall be left in place while the 
pressure test is being performed; 

f) The pressure gage shall be located at the 
tip of the vessel during the test; and 



Re-closing pressure relief devices must be 
removed from the tank and tested separately 
unless they can be tested while installed on 
the portable tank. 



S6.1 4.6.4 SPECIFICATION IM OR 
UN PORTABLE TANKS 

All Specification IM or UN portable tanks, 
except for UN portable tanks used for non- 
refrigerated and refrigerated liquefied gases, 
and all piping, valves, and accessories, except 
pressure relief devices shall be hydrostatically 
tested with water, or other liquid similar in 
density and viscosity as follows: 

a) All IM portable tanks used for non-refriger- 
ated and refrigerated liquid gases shall be hy- 
drostatically tested with water to a pressure 
of not less than 1 50% of the portable tanks 
maximum allowable working pressure; 

b) All UN portable tanks used for the trans- 
portation of non-refrigerated liquefied gases 
shall be hydrostatically tested, with water 
to a pressure not less than 130% of the 
portable tanks maximum allowable work- 
ing pressure. 

1) UN portable tanks used for the trans- 
portation of refrigerated gases should 
be tested by either hydrostatically or 
pneumatically using an inert gas to a 
pressure of not less than 1 .3 times the 
design pressure of the portable tank. 

2) If the portable tank is subjected to the 
pneumatic test method, the owner-user 
shall take necessary precautions for the 
safety of the inspection and test person- 
nel. 

3) The pneumatic test pressure shall be 
reached gradually by increasing the test 
pressure to one-half of the test pressure. 
Once this pressure is reached, the test 
pressure will be increased in incre- 
ments of approximately one-tenth of 



244 



NATIONAL BOARD INSPECTION CODE 



PART 2 



INSPECTION 



cl) 



the test pressure until the required test 
pressure is reached. 

4) When the test pressure is reached, the 
pressure shall be reduced to a value 
equal to four-fifths of the test pressure 
and held for a sufficient time to permit 
the inspection for leaks. 

The minimum test pressure of IM and UN 
portable tanks is determined on the basis of 
the hazardous materials that are intended 
to be transported in the portable tank as 
required by CFR Title 49, Part 1 72.1 01 . 

For liquid, solid, and non-refrigerated gases, 
the minimum test pressure for a specific 
hazardous material is provided in the ap- 
plicable "T" Codes assigned for a particular 
hazardous material, as specified in CFR 
Title 49, Part 172.102 Tables. See Table 
S6.1 4.6.4. 



thereafter, a successful pressure test is con- 
ducted in accordance with this section. 

1) Any permanent distortion of the por- 
table tank exceeding that permitted by 
the applicable specification; 

2) Any leakage; or 

3) Any deficiencies that would render the 
portable tank unsafe for transportation. 

g) The approval agency shall witness the hy- 
drostatic or pneumatic tests. 

h) If the portable tank is damaged or a defi- 
ciency is discovered that might render the 
portable unsafe, the tank shall be repaired 
to a satisfactory condition. This test shall 
be witnessed by the applicable approval 
agency. As a minimum, the repair proce- 
dures shall include: 



Table S6.1 4.6.4 
"T" Codes 



T1 toT22 



T23 



For liquid and solid hazardous mate- 
rials of Classes 3 through 9 that are 
transported in portable tanks. 1 



Applies to self-reactive substances of 
Division 4.1 and organic peroxides 
of Division 5.2. 



T50 Applies to liquefied compressed 

gases. 

Note: Class numbers of hazardous materials 
isted in CFR 49, Part 173.2. 



While the portable tank is under test pres- 
sure, it shall be inspected for leakage, 
distortion, or any other condition that 
might render the portable tank unsafe for 
service. 

If a portable tank fails to meet the require- 
ments of the pressure test or if during the 
pressure test there are any of the following 
conditions, the portable tank shall be re- 
moved from transportation service, unless 
the portable tank is adequately repaired and, 



1) Retesting to the original pressure test 
requirements. 

2) If the hydrostatic or pneumatic test is 
successful, the witnessing approval 
agency shall apply its name, identify- 
ing mark, or identifying number on the 
portable tank's nameplate as required 
in S6.14.7 of this section. 

All thermal cutting or welding on the shell 
of IMor UN portable tanks shall be done in 
accordance with this section. After comple- 
tion of the thermal cutting or welding op- 
eration, a pressure test shall be performed 
to the requirements of the portable tank's 
original test requirements. 



S6.14.7 INSPECTION AND TEST 

MARKINGS FOR IM OR UN 
PORTABLE TANKS 

a) Each IMor UN portable tank shall be durably 
and legibly marked, in English, with the date 
(month and year) of the last pressure test. 



245 



NATIONAL BOARD INSPECTION CODE • PART 2 — INSPECTION 



b) The identifying agency shall witness the 
test, when required, and the date of the last 
visual inspection. 

c) The markings required on the portable 
tank's identification plate shall be identified 
as follows: 

1 ) Placed on or near the metal identifica- 
tion plate; 

2) The size of the letters and numerals on 
the plate shall be no less than 3mm (0.1 
inches) high; and 

3) If the letters and numerals are stamped 
into the portable tank's shell, they shall 
be at least 12mm (0.5 inches) high. 



S6.14.8 INSPECTION AND TEST 
MARKINGS FOR 
SPECIFICATION DOT 51, 56, 57, 
OR 60 

a) Each Specification DOT 51, 56, 57, or 60 
portable tank shall be durably and legibly 
marked, in English, with the date (month 
and year) of the most recent periodic test. 

b) The markings shall be placed near the 
metal certification plate and shall be in 
accordance with the following: 

1) Shall be marked on a non-removable 
component of the portable tank that 
identifies the specification markings; 

2) Located in an unobstructed area with 
letters and numerals identifying the 
standard or specification, e.g., UN 1 A1 , 
DOT 4B240ET, etc.; 

3) Shall identify the name and address or 
symbol of the portable tank manufac- 
turer or, where specifically authorized, 
the symbol of the approval agency 
certifying compliance with the UN 
standard; 



4) The markings shall be stamped, em- 
bossed, burned, printed, or otherwise 
marked on the portable tank to provide 
adequate accessibility, permanency, 
contrast, and legibility, so as to be read- 
ily apparent and understood; and 

5) The letters and numerals shal I be at least 
3 mm (0.1 inches) high if stamped on 
a plate, and shall be at least 12.0 mm 
(0.5 inches) high when stamped on the 
portable tank's shell. 



S6.14.9 RECORD RETENTION 

The owner of each portable tank or his autho- 
rized agent shall retain a written report of the 
date and results of all required inspections and 
tests, including the following: 

a) If applicable, the ASME Manufacturer's 
Data Report (U-1 or U1 A Forms); 

b) The name and address of the person per- 
forming the inspection and/or test in accor- 
dance with the applicable specification; 

c) The manufacturer's data report including a 
certificate(s) signed by the manufacturer; 

d) The authorized agency, as applicable, in- 
dicating compliance with the applicable 
specification of the portable tank; and 

e) The records shall be retained in the owner's 
files or should be retained by the owner's 
authorized agent during the time that the 
portable tank is used. These records do not 
have to be maintained for DOT 56 and DOT 
57 Specification tanks. 



S6.15 GENERAL REQUIREMENTS FOR 

DOT SPECIFICATION 106A AND 
1 1 0A TANK CARS (TON TANKS) 

All Specification DOT 106A and DOT 110A 
multi-unit ton tanks shall be cylindrical, cir- 



246 



NATIDNAL BOARD INSPECTION CODE • PART 2 



INSPECTION 



cular in cross section and shall have heads 
of an approved design, with all fittings, i.e., 
couplings, nozzles, etc., located in the heads 
of the tank. 



S6.1 5.1 SPECIAL PROVISIONS FOR 
TON TANKS 

49 CFR, Section 179.300 has specific criteria 
for ton tanks that shall be met to satisfy DOT 
Specification 1 06A and 1 1 0A. The limitations 
are as follows: 

a) Ton tanks shall have a water containing ca- 
pacity of at least 1 500 pounds (0.68 tonne), 
but in no case can the water containing ca- 
pacity of the ton tank exceed 2600 pounds 
(1.18 tonne); 

b) Ton tanks shall not be insulated; 

c) Thickness of plates for DOT Specification's 
106A and 110A ton tanks shall be in ac- 
cordance with Table S6.1 5.1 -a; 

d) The maximum carbon content for carbon 
steel used in the fabrication of ton tanks 
shall not exceed 0.31 percent; 

e) Permitted materials can be either an ASME, 
SA material, or an ASTM Material permitted 
by Table S6.1 5.1 -b; 

f) DOT Specification 106A ton tanks shall 
only use forged-welded heads, convex to 
pressure. The forged-welded heads shall 
be torispherical with an inside radius not 
greater than the inside diameter of the shell. 
The heads shall be one piece, hot formed in 
one heat so as to provide a straight flange 
at least 4 inches (1 00 mm) long. The heads 
must have a snug fit into the shell; 

g) DOT Specification 110A ton tanks shall 
only use fusion-welded heads formed con- 
cave to pressure. The fusion-welded heads 
shall be an ellipsoid of 2:1 ratio and shall 
be of one piece, hot formed in one heat so 



as to provide a straight flange at least 1-1/2 
inches (38 mm) long; 

h) All longitudinal welded joints on DOT 
Specification 1 06A and DOT Specification 
1 10Aton tanks shall be a fusion weld. DOT 
Specification 106A ton tank head to shell 
attachments shall be a forged-welded joint. 5 
DOT Specification 1 10A ton tank head to 
shell attachments shall be a fusion weld; 

i) Postweld heat treatment is required after 
welding for all DOT Specification 106A 
and Specification 1 1 0A ton tanks; 

j) DOT Specification 106A and DOT Speci- 
fication 1 1 0A ton tanks shall be of such a 
design as to afford maximum protection 
to any fitting or attachment to the head, 
including loading and unloading valves. 
The protection housing 5 shall not project 
beyond the end of the ton tanks and shall 
be securely fastened to the tank head; 

k) If applicable, siphon pipes and their cou- 
plings on the inside of the ton tank's head 
and lugs on the outside of the tank head for 
attaching valve protection housing shall be 
fusion welded prior to performing postweld 
heat treatment; 

I) DOT Specification 106A and DOT Speci- 
fication 1 10A ton tanks are required to be 
equipped with one or more approved types 
of pressure relief devices. The device shall 
be made out of metal and the pressure 
relief devices shall not be subject to rapid 
deterioration by the lading. The device's 
inlet fitting to the tank shall be a screw-type 
fitting and installed or attached directly into 
the ton tank's head or attached to the head 
by other approved methods. For thread 
connections, the following shall apply: 

1) The threaded connections for all open- 
ings shall be in compliance with the 



5 The forged-welded joint shall be thoroughly hammered or 
rolled to insure a sound weld. 



Z47 



NATIONAL BDARD INSPECTION CODE ' PART Z 



INSPECTION 



TableS6.15.1-a 

Thickness of Plates and Safety Valve Requirements 



DOT Specification ; 106A500-X 106A800-X ;• 110A500-W 110600-W : 110A800-VV 


110A1000-W 


Minimum required 
bursting pressure, psig 
(MPa) 


None 
Specified 


None 
Specified 


1,250 
(8.62) 


1,500 
(10.34) 


2,000 
(13.8) 


2,500 

(17.2) 


Minimum thickness 
shell, inches (mm), 
Test Pressure (See CFR 
179.300-15), psi (MPa) 


13/32 

(10mm) 

500 

(3.45) 


11/16 

(1 7mm) 

800 

(5.52) 


11/32 

(10mm) 

500 

(3.45) 


3/8 

(10mm) 

600 

(4.41) 


15/32 

(12mm) 

800 

(5.52) 


19/32 

(1 5mm) 

1,000 

(6.89) 


Start-to-discharge, 
or burst pressure 
(maximum psi [MPa]) 


375 
(2.59) 


600 

(4.14) 


375 
(2.59) 


450 
(3.10) 


600 

(4.14) 


700 

(4.83) 



TabIeS6.15.1-b 

Acceptable Materials with Acceptable Tensile Strength and Elongation Requirements 



Material Specification 


Minimum Tensile Strength (psi) (MRa) 
in the welded condition. 

These values are to be used in the 
design calculations. 


Minimum Elongation in 2 in. (50 mm) 
(percent) in the welded condition. 

These values are to be used in the 
design ca leu la lion s . 


AS I M A 240 typo 304 


75,000(517,1 


25 


ASTM A 240 type 3041. 


70,000 (483) 


25 


ASTMA240type316 


75,000 (517; 


25 


ASTM A 240 type 31 6L 


70,000(483) 


25 


ASTM A 240 type 321 


75,000 (51 7) 


25 


ASTM A 285 Gr. A 


45,000:310) 


29 


ASTM A 285 Cr. B 


50,000 (345) 


20 


ASTM A 285 Gr. C 


55,000 (380) 


20 


ASTM A 515 Gr. 65 


65,000 14481 


:>o 


ASTM A 515 Gr. 70 


70,000 1483) 


20 


ASTM A 516 Gr. 70 


70,000 (483) 


20 



24B 



NATIONAL BOARD INSPECTION CODE 8 PART 2 



INSPECTION 



National Gas Taper Threads (NGT); 

2) Pressure relief devices shall be set for 
start-to-discharge and rupture discs shall 
burst at a pressure not exceeding the 
pressure identified in Table S6.1 5.1 -a. 



m) Fusible plugs if used shall be required to 
relieve the pressure from the tank at a tem- 
perature not exceeding 1 75°F (79°C) and 
shall be vapor tight at a temperature not 
exceeding 130°F(54°C). 



S6.15.2 VISUAL INSPECTION OF 
TON TANKS 

Without any regard to any other periodic in- 
spection and test requirements, a ton tank shall 
be visually inspected for evidence of any: 

a) Defects in welds; 

b) Abrasions; 

c) Corrosion; 

d) Cracks; 



e) Dents; 

f) Distortions; or 

g) Any other conditions that might make the 
ton tank unsafe for transportation. 



S6.15.3 INSPECTION AND TESTS OF 
DOT SPECIFICATION 106A 

AND DOT SPECIFICATION 11 OA 
TON TANKS 

Each ton tank shall be retested by subjecting 
the ton tank to a hydrostatic test in accordance 
with Table S6.15.3. The hydrostatic test shall 
include an evaluation of the tank's permanent 
expansion. As a minimum the hydrostatic test 
and the expansion procedure shall include: 

a) The hydrostatic test pressure shall be main- 
tained for a minimum of 30 seconds. This 
time period may be extended as long as 
necessary to secure complete expansion 
of the ton tank. 

b) The pressure gage used for the hydrostatic 



Table S6.1 5.3 

Ton Tank P eriodic Inspection and Test Frequencies 





Retest Interval, years 


Minimum Retest 
Pressure, psig (MPa) 


Pressure 
Pressure 


Relief Valve 
psig (MPa) 


DOT 
Specification 


Tank 


Pressure 
Relief 
Device 


Tank 

Hydrostatic 

Expansion 


Tank Air 
Test 


Start-to- 
Discharge 


Vapor 

Tight 

| 300(2.07) 


106A500 


5 


2 


S00 (3.45) 


100(0.69) 


375 (2.59) 


106A500X 


5 


2 


500 (3.45) 


100(0.69) 


'.75 (2.59) 


-i 

| 300(2.07) 


1 06A800 


5 


2 


800(5.52) 


100(0.69) 


600(4.14) 


; 480(3.31) 


106A800X 


5 


2 


800(5.52) 


100(0.69) 


600(4.14) 


I 480(3.31) 


106A800NCI 


5 


2 


800 (5.52) 


100(0.69) 


600(4.14) 


I 480(3.31) 


110A500-W 


5 


2 


500 (3.45) 


100(0.69) 


375 (2.59) 


300(2.07) 


110A600-W 


5 


2 


600(4.41) 


100(0.69) 


500 (3.45) 


360(2.48) 


1 1 0A800-W 


5 


2 


800 (5.52) 


100(0.69) 


600(4.14) 


! 480(3.31) 


110A1000-W 


5 


2 


1,000(6.89) 


100(0.69) 


750(5.17) 


J 600(4.41) 



249 



NATIONAL BOARD INSPECTION CODE • PART 2 



INSPECTION 



test shall be accurate within one percent of 
the range of the pressure gage. The accuracy 
of the pressure gage shall be verified prior 
to performing the hydrostatic test. 

c) The expansion test procedure shall include 
the following requirements: 

1) The expansion shall be recorded in 
cubic cm; 

2) Permanent volumetric expansion shall 
not exceed 1 0% of the total volumetric 
expansion at the test pressure; and 

3) The expansion gage shall be accurate 
within one percent of the hydrostatic 
test pressure. 

d) The ton tank shall not show any signs of 
leakage or stress during the hydrostatic and 
expansion test. 

e) The retest may be made at any time during 
the calendar year the retest falls due. 



S6.1 5.3.1 AIR TESTS 

a) Al I specification DOT 1 06A and DOT 1 1 0A 
ton tanks, in addition to the hydrostatic 
test shall be subjected to an air test at fre- 
quencies and pressures specified in Table 
S6.15.3. 

b) The air test shall be under positive control 
to ensure safety to all inspection and test 
personnel. 

c) Any leakage observed will require the ton 
tank to be repaired and retested prior to 
placing the ton tank back into service. 



S6.15.3.2 PRESSURE RELIEF DEVICE 

TESTING 

All pressure relief devices shall be retested by 
air or gas for the start-to-discharge and vapor 
tightness requirements atfrequencies and pres- 
sures specified in Table S6.1 5.3. 



S6.15.3.3 RUPTURE DISCS AND FUSIBLE 
PLUGS 

All rupture discs required by S6.15.1 (l)(2) and 
fusible plugs required by S6.15.1(m) shall be 
removed from the ton tank and inspected. The 
inspection shall include but not limited to the 
following: 

a) All rupture discs shall be inspected for 
corrosion, leakage, and manufacturer toler- 
ances; 

b) All fusible plugs shall be inspected for cor- 
rosion, loose, or deteriorated temperature 
sensitive materials; 

c) Any indication specified in (a) and (b) above 
will require the rupture disc or fusible plug 
to be replaced with devices specified in 
S6.1 5.1 (l)(2) and S6.1 5.1 (m) of this section. 



S6.15.3.4 SUCCESSFUL COMPLETION OF 
THE PERIODIC RETESTING 

If the results of the periodic retest are successful, 
the ton tank shall be plainly and permanently 
stamped on one head or chime of each ton 
tank. The stamping shall include: 

a) The month and year of the test followed by 
a "V", and 

b) Dates of previous tests and all prescribed 
markings shall not be removed. Previous 
dates and markings on the ton tank's head 
or chime shall be legible. 



250 



NATIONAL BOARD INSPECTION CODE • PART 2 — INSPECTION 



S6.15.3.5 EXEMPTIONS TO PERIODIC 
HYDROSTATIC RETESTING 

Ton tanks that satisfy DOT 1 06A and DOT 1 1 0A 
that are used exclusively for transporting fluori- 
nated hydrocarbons and mixtures thereof, and 
are free from corroding components related to 
the ton tank may be exempted from the periodic 
hydrostatic retest if: 

a) The ton tank is given a complete internal 
and external visual inspection of all heads, 
shells, nozzles, couplings, pressure relief 
devices, i.e. pressure relief valves and rup- 
ture discs and fusible plugs for deterioration 
and leakage. 

b) The visual internal and external inspec- 
tion is performed by qualified personnel, 
i.e., registered inspector, employee of the 
owner-user, etc. 



S6.1 5.3.6 RECORD OF RETEST 

INSPECTION 

The owner or the person performing the re- 
quired pressure test and visual inspection is 
required to retain a written record of the results 
as long as the ton tank is in service. The written 
report shall identify the following: 

a) Date of the test and inspection; 

b) DOT Specification Number of the ton 
tank; 

c) Ton tank identification: registered symbol 
and serial number, date of manufacture, 
and ownership symbol; 

d) Type of protective coating, i.e., painting, 
etc.; 

e) Statement as to the need for refinishing or 
recoating the ton tank; 

f) Conditions checked for: 
1 ) leakage; 



2) corrosion; 

3) gouges; 

4) dents or dings; 

5) broken or damaged chimes, or protec- 
tive rings; 

6) fire damage; 

7) internal conditions; 

8) test pressure; and 

9) the written report shall also identify the 
results of the test: 

a. disposition of the tank, i.e., returned 
to service, returned to the manufac- 
turer for repair, or scrapped; and 

b. Identification of the person per- 
forming the retest or inspection. 



S6.15.4 STAMPING REQUIREMENTS 

OF DOT 1 06A AND DOT 1 1 0A 

TON TANKS 

To identify compliance with CFR 179.300-1 
each DOT 1 06A and DOT 1 1 0A ton tank shall 
be plainly and permanently stamped with let- 
ters and figures 3/8 of an inch high on valve 
end chime of the ton tank's head. The minimum 
requirements for the stamping are as follows: 

a) DOT Specification Number; 

b) Material and cladding material if any. This 
information shall be stamped directly be- 
low the DOT Specification Number; 

c) Owner's or builder's identifying symbol 
and serial number. This information shall 
be stamped directly below the material 
identification stamping. The owner's or 
builder's symbol shall be registered with 
the Bureau of Explosions (duplications are 
not authorized); 



25 1 



NATIONAL BOARD INSPECTION CODE • PART 2 — INSPECTION 



cl) Inspector's official mark. This information 
shall be stamped directly below the owner's 
or builder's symbol; 

e) Date of the original ton tank test (month 
and year). Provisions should be made 
that subsequent tests may easily be added 
thereto; 

f) Water capacity of the ton tank in pounds; 

g) A duplicate of the stamping that satisfies 
(a) through (f) should be used if the plate is 
made of brass and is permanently attached 
to the ton tank's head. 



S6.16 



DEFINITIONS 



These Definitions shall be used in conjunction 
with those of Section 9 of the NBIC. Where 
conflicts between the two arise, those listed 
below shall prevail. 

Approval — A written authorization, includ- 
ing a competent authority approval from the 
Associate Administrator or other designated 
department official, to perform a function for 
which prior authorization by the Associate 
Administrator is required. 

Approval Agency — An organization or a per- 
son designated by the DOT to certify packaging 
as having been designed, manufactured, tested, 
modified, marked, or maintained in compli- 
ance with applicable DOT regulations. 

Approved — Approval issued or recognized by 
the department unless otherwise specifically 
indicated. 

Appurtenance — Any attachment to a cargo 
tank that has no lading retention or containment 
function and provides no structural support to 
the cargo tank. 

Associate Administrator — The Associate Admin- 
istrator for Hazardous Materials Safety, Research, 
and Special Programs Administration. 



Atmospheric Gas — Air, nitrogen, oxygen, 
argon, krypton, neon, and xenon. 

Attachments — Structural Members means 
the suspension sub-frame, accident protection 
structures, external circumferential reinforce- 
ments, support framing, and kingpin sub-frame 
(upper coupling). 

Attachments Light Weight — Welded to a 
cargo tank wall such as a conduit clip, brake 
line clip, skirting structure, lamp mounting 
bracing, or placard holder. 

Authorized inspector (AI) — An inspector 
regularly employed by an ASME-accredited 
Authorized Inspection Agency (AIA) who has 
been qualified to ASME developed criteria, to 
perform inspections under the rules of any Ju- 
risdiction that has adopted the ASME Code. 

Baffle — A nonliquid-tight transverse partition 
device that deflects, checks, or regulates fluid 
motion in a tank. 

Bar — 1 BAR = 1 00 kPa (1 4.5 psi) 

Bottle — An inner packaging having a neck of 
relatively smaller cross section than the body 
and an opening capable of holding a closure 
for retention of the contents. 

Bottom Shell — That portion of a tank car sur- 
face, excluding the head ends of the tank car 
that lies within two feet, measured circumfer- 
entially, of the bottom longitudinal center line 
of the tank car tank. 

Bulk Packaging — A packaging other than the 
vessel or a barge, including a transport vehicle 
or freight container, in which hazardous mate- 
rials are loaded with no intermediate form of 
containment and which has: 

a) A maximum capacity greater than 450L 
(1 1 9 gallons) as a receptacle for a liquid; 

b) A maximum net mass greater than 400 kg 
(882 pounds) and a maximum capacity 



252 



NATIONAL BOARD INSPECTION CODE • PART 2 — INSPECTION 



greater than 450L (1 1 9 gallons) as a recep- 
tacle for a solid; or 

c) A water capacity greater than 454 kg (1 000 
pounds) as a receptacle for a gas. 

Bulkhead — A liquid-tight transverse closure 
at the ends of or between (compartment) cargo 
tanks. 

Cargo Tank — A bulk packaging which: 

a) Is a tank intended primarily for the car- 
riage of liquids or gases and includes ap- 
purtenances, reinforcements, fittings, and 
closures; 

b) Is permanently attached to or forms a part 
of a motor vehicle, or is not permanently 
attached to a motor vehicle but which, 
by reason of its size, construction, or at- 
tachment to a motor vehicle is loaded or 
unloaded without being removed from the 
motor vehicle; and 

c) Is not fabricated under a specification for 
cylinders, portable tanks, tank cars, or 
multi-unit tank car tanks. 

Cargo Tank Motor Vehicle — A motor vehicle 
with one or more cargo tanks permanently 
attached to or forming an integral part of the 
motor vehicle. 

Carrier — A person engaged in the transporta- 
tion of passengers or property by: 

a) Land or water, as a common, contract, or 
private carrier; or 

b) Civil aircraft. 

Certified Individual — An individual that is 
qualified and certified by a manufacturer ac- 
credited by ASME to construct Class 3 Section 
XII Transport Tanks. 

Combination Packaging — A combination of 
packaging for transport purposes, consisting 
of one or more inner packaging secured in a 



non-bulk outer packaging. It does not include 
a composite packaging. 

Combustible Liquid — Any liquid that does not 
meet the definition of any other hazard class 
specified in 1 73.1 29 of Title 49 and has a flash 
point above 60.5°C (1 41 .5°F) and below 93°C 
(100°F). 

Competent Authority — A national agency 
responsible under its national law for the 
control or regulation of a particular aspect of 
the transportation of hazardous materials. In 
the United States, the Associate Administrator 
of the US Department of Transportation is the 
Competent Authority. 

Composite Packaging — A packaging consist- 
ing of an outer package and an inner receptacle 
so constructed that the inner receptacle and the 
outer package are integral. Once assembled, 
it remains an integrated single unit. It is filled, 
stored, shipped, and emptied as such. 

Compressed Gas in Solution — A non-liquefied 
compressed gas that is dissolved in a solvent. 

Constructed and Certified in Accordance with 
the ASME Code — A cargo tank that is con- 
structed and stamped in accordance with the 
ASME Code and is inspected and certified by 
an Authorized Inspector, Qualified Inspector, 
or a Certified individual. 

Corrosive Material — A liquid or solid that 
causes full thickness destruction of human skin 
at the site of contact within a specified period 
of time. A liquid that has a severe corrosion 
rate on steel or aluminum based on the criteria 
in 1 73.1 73(c) (3) of Title 49 is also a corrosive 
material. 

Cryogenic Liquid — A refrigerated liquefied 
gas having a boiling point colder than -90°C 
(-1 30°F) at 1 01 .3 kPa (1 4.7 psia) absolute. 

Design Certification — That each cargo tank or 
cargo tank motor vehicle design type, including 
its required accident damage protection device, 
must be certified to conform to the specification 



253 



NATIONAL BOARD INSPECTION CODE • PART 2 — INSPECTION 



requirements by a Design Certifying Engineer 
who is registered with the department. An 
accident damage protection device is a rear- 
end protection, overturn protection, or piping 
protection. 

Design Certifying Engineer — A person regis- 
terd with the department in accordance with 
Subpart F of Part 107 of 49 CFR who has the 
knowledge and ability to perform stress analysis 
of pressure vessels and otherwise determine 
whether a cargo tank design and construction 
meets the applicable DOT specification. In 
addition, Design Certifiying Engineer means a 
person who meets, at a minimum, any one of 
the following: 

a) Has an engineering degree and one year of 
work experience in cargo tank structural or 
mechanical design; 

b) Is currently registered as a professional 
engineer by the appropriate authority of a 
state of the United States or a province of 
Canada; or 

c) Has at least three years experience in per- 
forming the duties of a Design Certifying 
Engineer by September 1, 1991, and was 
registered with the department by Decem- 
ber 31, 1995. 



Design Type 
are made: 



One or more cargo tanks that 



a) to the same specification; 

b) by the same manufacturer; 

c) to the same engineering drawings and 
calculations, except for minor variations in 
piping that do not affect the lading retention 
capabilities of the cargo tank; 

d) of the same materials of constructions; 

e) to the same cross-sectional dimensions; 

f) to a length varying by no more than 5 per- 
cent; 



g) with the volume varying by no more than 5 
percent (due to the change in length only); 
and 

h) for the purposes of 1 78.338 of Title 49 only, 
with the same insulation system. 

DOT or Department — US Department of 
Transportation. 

Elevated Temperatures Material — A mate- 
rial which, when offered for transportation or 
transported in a bulk packaging: 

a) Is in a liquid phase and at a temperature at 
or above 100°C (212 °F); 

b) Is in a liquid phase with a flash point at or 
above 37.8°C (100°F) that is intentionally 
heated and offered for transportation, or 
transported at or above the flash point; or 

c) Is in a solid phase and at a temperature at 
or above 240°C (464°F). 

Extreme Dynamic Loadings — The maximum 
loading of a cargo tank motor vehicle may 
experience during its expected life, excluding 
accident loadings resulting from an accident, 
such as overturn or collision. 

Flammable Gas — Any material that is a gas at 
20°C (68°F) or less and 101.3 kPa (14.7 psia) 
of pressure [a material that has a boiling point 
of 20°C (68°F) or less at 1 01 .3 kPa (1 4.7 psia)] 
which: 

a) Is ignitable at 1 01 JkPa (1 4.7 psia) when in 
a mixtue of 13 percent or less by volume 
with air; or 

b) Has a flammable range at 1 01 .3kPa (1 4.7 
psia) with air of at least 1 2 percent regard- 
less of the lower limit. Except for aerosols, 
the limits specified in paragraphs (1) and 
(2) shall be determined at 101.3kPa (14.7 
psia) of pressure and a temperature of 20°C 
(68°F) in accordance with the ASTM E681 - 
85, Standard Test Method for Concentration 



254 



NATIONAL BOARD INSPECTION CODE 



PART 2 



INSPECTION 



Limits of Flammability of Chemicals, or 
other equivalent method approved by the 
Associate Administrator, Hazardous Mate- 
rial Safety. 

Gas — A materia] that has a vapor pressure 
greater than 300 kPa (43.5 psia) at50°C (122°F) 
or is completely gaseous at 20°C (68°F) at a 
standard pressure of 1 01 .3 kPa (1 4.7 psia). 

Gross Weight or Gross — The weight of a pack- 
aging plus the weight of its contents. 

Hazardous Class — The category of hazard 
assigned to a hazardous material under the 
definitional criteria of part 1 73 of Title 49 and 
the provisions of the 172.101 Table. A material 
should meet the defining criteria for more than 
one hazard class but is assigned to only one 
hazard class. 

Hazardous Material — A substance or material 
that the Secretary of Transportation has deter- 
mined is capable of posing an unreasonable 
risk to health, safety, and property when trans- 
ported in commerce and has been designated 
as hazardous under section 5103 of Federal 
Hazardous Law (49 U.S.C. 5103). The term 
includes hazardous substances, hazardous 
wastes, marine pollutants, elevated tempera- 
ture materials, materials designated as hazard- 
ous in the Hazardous Material Table (49 CFR 
1 72.1 01 ), and materials that meet the defining 
criteria for hazard classes and divisions of 1 73 
of subchapter C of 1 71 .8 of Title 49. 

Hazardous Zones — One of four levels of haz- 
ard (Hazard Zones A through D) as assigned to 
gases, as specified in 1 73.1 1 6(a) of Title 49, and 
one of two levels of hazard (Hazard Zones A 
and B) assigned to liquids that are poisonous by 
inhalation as specified in 1 73.1 33(a) ofTitle 49. 
A hazard zone is based on the LC 50 value for 
acute inhalation toxicity of gases and vapors. 

High Pressure Liquefied Gas — A gas with a 
critical temperature between -50°C (-58°F) and 
+ 65°C(149°F). 



Inner Packaging — A packaging for which 
an outer packaging is required for transport. 
It does not include the inner receptacle of a 
composite packaging. 

Inner Receptacle — A receptacle that requires 
an outer packaging in order to perform its con- 
tainment function. The inner receptacle should 
be an inner packaging of a combination pack- 
aging or the inner receptacle of a composite 
packaging. 

Inspection Pressure — The pressure used to 
determine leak tightness of the cargo tank 
when testing with pneumatic or hydrostatic 
pressure. 

Lading — The hazardous material contained 
in the cargo tank 

Liquefied Compressed Gas — a gas when 
packaged under pressure for transportation is 
partially liquid at temperatures above -50°C 
(-58°F). 

Liquid — A material, other than an elevated 
temperature material, with a melting point or 
initial melting point of 20°C (68°F) or lower at 
a standard pressure of 101.3 kPa (14.7 psig). 
Liquid Phase means a material that meets 
the definition of liquid when evaluated at the 
higher of the temperature at which it is offered 
for transportation or at which it is transported, 
not atthe 37.8 °C (1 00°F) temperature specified 
in ASTM D 4359-84. 

Low Pressure Liquefied Gas — A gas with a 
critical temperature above + 65°C (149°F). 

Manufacturer — Any person engaged in the 
manufacture of a DOT specification cargo tank, 
cargo tank motor vehicle, or cargo tank equip- 
ment that forms part of the cargo tank wall. 
This term includes attaching a cargo tank to a 
motor vehicle or to a motor vehicle suspension 
component that involves welding on a cargo 
tank wall. A manufacturer must register with 
the department in accordance Subpart F of Part 
107 in Subpart A of 49 CFR. 



255 



NATIONAL BOARD INSPECTION CODE • PART Z 



INSPECTION 



Marking — A descriptive name, identifica- 
tion number, instructions, cautions, weight, 
specification, or UN marks, or combinations 
thereof, required by Title 49 on outer packaging 
or hazardous materials. 

Mode — Any of the following transportation 
methods: rail, highway, air, or water. 

Modification — Any change to the original 
design and construction of a cargo tank or a 
cargo tank motor vehicle that affects its struc- 
tural integrity or lading retention capability 
including changes to equipment certified as 
part of an emergency discharge control system. 
Any modification that involves welding on the 
cargo tank wall must also meet ail requirements 
for "Repair" as defined in this section. Excluded 
from this catagory are the following: 

a) A change to motor vehicle equipment 
such as lights, truck, or tractor power train 
components, steering, and brake systems, 
suspension parts, and changes to appurte- 
nances, such as fender attachments, light- 
ing brackets, ladder brackets; and 

b) Replacement of components such as valves, 
vents, and fittings with a component of a 
similar design and of the same size. 

Motor Vehicle — A vehicle, machine, trac- 
tor, trailer, or semi-trailer, or any combination 
thereof, propelled or drawn by mechanical 
power and used upon the highways in the 
transportation of passengers or property. It does 
not include a vehicle operated exclusively on a 
rail or rails or a trolley bus operated by electric 
power derived from a fixed overhead wire, fur- 
nishing local passenger transportation similar 
to street-railway service. 

Multi-Specification Cargo Tank Motor Vehicle 
— A cargo tank with two or more cargo tanks 
fabricated to more than one cargo tank speci- 
fication. 



Non-Liquefied Compressed Gas — when pack- 
aged under pressure for transportation is entirely 
gaseous at -50°C (-58°F) with a critical tempera- 
ture less than or equal to -50°C (-58°F). 

Normal Operating Loading — A cargo tank 
motor vehicle equipped with two or more cargo 
tanks fabricated to more than one cargo tank 
specification. 

Operator — A person who controls the use of 
aircraft, vessel, or vehicle. 

Outer Packaging — The outermost enclosure of 
a composite or combination packaging together 
with any absorbent material, cushioning, and 
any other components necessary to contain and 
protect inner receptacles or inner packaging. 

Owner — The person who owns a cargo tank 
motor vehicle used for the transportation of 
hazardous materials, or that person's autho- 
rized agent. 

Packaging — A receptacle and any other 
components or materials necessary for the 
receptacle to perform its containment function 
in conformance with the minimum packing 
requirements of Title 49. 

Packing Group — A grouping according to the 
degree of danger present by hazardous mate- 
rials. Packing Group I indicates great danger; 
Packing Group II indicates medium danger; 
Packing Group III indicates minor danger. 

Person — An individual, firm, co-partnership, 
corporation, company, association, or joint- 
stock (including any trustee, receiver, assignee, 
or similar representative); or any government or 
Indian tribe (or an agency or instrumentality of 
any government or Indian tribe) that transports 
hazardous material to further a commercial 
enterprise or offers a hazardous material for 
transportation in commerce. 



256 



NATIONAL BOARD INSPECTION CODE • PART Z — INSPECTION 



Poisonous Gas — A material that is a gas at 
20°C (68°F) or less and a pressure of 1 01 .3 kPa 
(14.7 psia) [a material that has a boiling point 
of 20°C (68°F) or less at 1 01 .3 kPa (1 4.7 psia] 
and which: 

a) Is known to be so toxic to humans as to 
pose a hazard to health during transporta- 
tion; or 

b) In the absence of adequate data on human 
toxicity, is presumed to be toxic to humans 
because when tested on laboratory animals 
it has an LC50. 

Poisonous Materia! — A material, other than a 
gas, which is known to be so toxic to humans as 
to afford a hazard to health during transporta- 
tion, or which in the absence of adequate data 
on human toxicity. 

Portable Tanks — A bulk packaging (except 
cylinder having a water capacity of 1000 
pounds or less) designated primarily to be 
loaded onto, or on, or temporarily attached to 
a transport vehicle or ship and equipped with 
skids, mountings, or accessories to facilitate 
handling of the tank by mechanical means. It 
does not include a cargo tank, tank car, multi- 
unit tank car tanks, or trailers carrying 3AX, 
3AAX, or 3T cylinders. 

psi — Pounds per square inch. 

psia — Pounds per square inch absolute. 

psig — Pounds per square inch gage. 

Qualified Inspector — An inspector regularly 
employed by an ASME Qualified Organiza- 
tion (QIO) who has been qualified to ASME 
developed criteria by a written examination, 
to perfom inspections under the rules of any 
jurisdiction that has adopted the ASME Code. 
TheQI shall not be in the employ of the manu- 
facturer. See ASME XII, TC-41 0. 

Rail Car — A car designed to carry freight or 
nonpassenger personnel by rail, and includes a 



box car, flat car, gondola car, hopper car, tank 
car, and occupied caboose. 

Rebarrelling — Replacing more than 50% of 
the combined shell and head material of a 
cargo tank. 

Receptacle — A containment vessel for receiv- 
ing and holding materials, including any means 
of closing. 

Registered Inspector (Ri) — A person regis- 
tered with the department in accordance with 
Subpart F of Part 1 07 of 49 CFR who has the 
knowledge and ability to determine whether a 
cargo tank conforms with the applicable DOT 
specification. In addition, Registered Inspector 
means a person who meets, at a minimum, any 
one of the following: 

a) Has and engineering degree and one year 
of work experience; 

b) Has an associate degree in engineering and 
two years of work experience; 

c) Has a high school diploma or General 
Equivalency Diploma and three years work 
experience; or 

d) Has at least three years experience perform- 
ing the duties of a Registered Inspector by 
September 1 , 1 991 , and was registered with 
the DOT by December 31, 1995. 

Repair — Any welding on a cargo tank wall 
done to return a cargo tank or a cargo tank mo- 
tor vehicle to its orginial design and construc- 
tion specification, or to a condition prescribed 
for a later equivalent specification in effect at 
the time of the repair. Excluded from this cat- 
egory are the following: 

a) A change to motor vehicle equipment 
such as lights, truck, or tractor power train 
components. Steering and brake systems, 
suspension parts, and changes to appurte- 
nances, such as fender attachments, light- 
ing brackets, ladder brackets; 



25V 



NATIONAL BPARD INSPECTION CODE • PART 2 — INSPECTION 



b) Replacement of components such as valves, 
vents, and fittings with a component of a 
similar design and of the same size; and 

c) Replacement of an appurtenance by weld- 
ing to a mounting pad. 

Replacement of a Barrel —To replace the ex- 
isting tank on a motor vehicle chassis with an 
unused (new) tank. 

SCF (standard cubic foot) — One cubic foot of 
gas measured at 60°F, and 14.7 psia. 

Single Packaging — A nonbulk packaging other 
than a combination packaging. 

Solid — A material that is not a gas or liquid. 

Solution — Any homogenous liquid mixture of 
two or more chemical compounds or elements 
that will not undergo any segregation under 
conditions normal to transportation. 

Specification Packaging — A packaging con- 
forming to one of the specifications or standards 
for packaging in Part 178 or Part 179 of Title 
49. 

Strong Outside Container — The outermost 
enclosure that provides protection against the 
unintentional release of its contents under con- 
ditions normally incident to transportation. 

Tanks — A container, consisting of a shell 
and heads that form the pressure vessel hav- 
ing opening designed to accept pressure tight 
fittings or closure, but excludes any appurte- 
nances, reinforcements, fittings, or closures. 

Test Pressure — The pressure to which a tank is 
subjected to determine structural integrity. 

Top Shell — The tank car surface, excluding the 
head ends and bottom shell of the tank car. 



Transport Vehicle — A cargo-car-carrying 
vehicle such as an automobile, van, tractor, 
truck, semi trailer, tank car, or rail car used for 
the transportation of cargo by any mode. Each 
cargo-carrying body (trailer, rail car, etc.) is a 
separate transport vehicle. 

UFC — Uniform Freight Classification. 

UN — United Nations. 

UN Portable Tank — An intermodal tank having 
a capacity of more than 450L (1 18.9 gallons). 
It includes a shell fitted with service equipment 
and structural equipment, including stabilizing 
members external to the shell and skids, mount- 
ings or accessories to facilitate mechanical 
handling. A UN portable tank must be capable 
of being filled and discharged without the 
removal of its structural equipment and must 
be capable of being lifted when full. Cargo 
tanks, rail tank car tanks, nonmetallic tanks, 
nonspecification tanks, bulk bins, and IBC's 
and packaging made to cylinder specifications 
are not UN portable tanks. 

UN Recommendation — The UN Recom- 
mendations on the Transport of Dangerous 
Goods. 

UN Standard Packaging — A conforming to 
standards in the UN Recommendations. 

Vessel — Includes every description of water- 
craft, used or capable of being used, as a means 
of transportation on the water. 

Viscous Liquid — A liquid material that has 
a measured viscosity in excess of 2500 cen- 
tistokes at 25°C (77°F), when determined in 
accordance with the procedures specified in 
ASTM Method D 445-72 "Kinematic Viscosity 
of Transparent and Opaque Liquids (and the 
Calculation of Dynamic Viscosity"), or ASTM 
Method D 1200-70 "Viscosity of Paints, Var- 
nishes, and Lacquers by Ford Viscosity Cup." 



Z5B 



NATIONAL BOARD INSPECTION CODE - PART Z 



INSPECTION 



SUPPLEMENT 7 

INSPECTION OF PRESSURE 
VESSELS IN LIQUEFIED 

PETROLEUM GAS (LPG) SERVICE 



S7.1 SCOPE 

a) Pressure vessels designed for storing LPG 
can be stationary or can be mounted on 
skids. LPG vessels are generally considered 
to be non-corrosive to the interior of the 
vessel. This part is provided for guidance 
of a general nature for the owner, user, or 
jurisdictional authority. There may be oc- 
casions where more detailed procedures 
will be required such as changing from 
one gas service to another (i.e., anhydrous 
ammonia to LPG). 

b) The application of this Supplement to un- 
derground vessels will only be necessary 
when evidence of structural damage to the 
vessel has been observed, leakage has been 
determined, or the tank has been dug up, 
and is to be reinstalled. 



6) National Board and/or jurisdictional 
registration number, if required. 

b) The vessel should be sufficiently cleaned 
to allow for visual inspection. 



S7.3 INSERVICE INSPECTION FOR 

VESSELS IN LP GAS SERVICE 

The type of inspection given to pressure vessels 
should take into consideration the condition 
of the vessel and the environment in which it 
operates. The inspection may be external or 
internal, and use a variety of nondestructive 
examination methods. Where there is no reason 
to suspect an unsafe condition or where there 
are no inspection openings, internal inspections 
need not be performed. When service condi- 
tions change from one service to another, such 
as ammonia to LPG, an internal inspection may 
be required. The external inspection may be 
performed when the vessel is pressurized or 
depressurized, but shall provide the necessary 
information that the essential sections of the 
vessel are of a condition to operate. 



S7.2 



PRE-INSPECTION ACTIVITIES 



a) A review of the known history of the pres- 
sure vessel should be performed. This 
should include a review of information, 
such as: 

1) Operating conditions; 

2) Historical contents of the vessel; 

3) Results of any previous inspection; 

4) Current jurisdictional inspection certifi- 
cate, if required; 

5) ASME Code symbol stamping or mark 
of code of construction, if required; 
and 



S7.3.1 NONDESTRUCTIVE 

EXAMINATION (NDE) 

Listed below are a variety of methods that may 
be employed to assess the condition of the 
pressure vessel. These examination methods 
should be implemented by experienced and 
qualified individuals. Generally, some form of 
surface preparation will be required prior to 
the use of these examination methods: visual, 
magnetic particle, liquid penetrant, ultrasonic, 
radiography, radioscopy, eddy current, metal- 
lographic examination, and acoustic emission. 
When there is doubt as to the extent of a defect 
or detrimental condition found in a pressure 
vessel, additional NDE may be required. 



259 



NATIONAL BOARD INSPECTION CODE • PART 2 — INSPECTION 



S7.4 



EXTERNAL INSPECTION 



All parts of the vessel shall be inspected for 
corrosion, distortion, cracking, or other condi- 
tions as described in this Section. In addition, 
the following should be reviewed, where ap- 
plicable: 

a) Insulation or Coating 

If the insulation or coating is in good con- 
dition and there is no reason to suspect an 
unsafe condition behind it, then it is not 
necessary to remove the insulation or coat- 
ing in order to inspect the vessel. However, 
it may be advisable to remove a small por- 
tion of the insulation or coating in order to 
determine its condition and the condition 
of the vessel surface. 

b) Evidence of Leakage 

Any leakage of vapor or liquid shall be 
investigated. Leakage coming from behind 
insulation or coating, supports, or evidence 
of past leakage shall be thoroughly investi- 
gated by removing any insulation necessary 
until the source is established. 



open to provide visual evidence of leak- 
age as well as to prevent pressure build 
up between the vessel and the reinforcing 
plate. Accessible flange faces should be 
examined for distortion. It is not intended 
that flanges or other connections be opened 
unless there is evidence of corrosion to 
justify opening the connection. 

Fire Damage 

Pressure vessels shall be carefully inspected 
for evidence of fire damage. The extent of 
fire damage determines the repair that is 
necessary, if any. See S7.7 



S7.5 



INTERNAL INSPECTION 



When there is a reason to suspect an unsafe 
condition, the suspect parts of the vessel shall 
be inspected and evaluated. 

The vessel shall be prepared and determined to 
be gas free and suitable for human entry prior 
to internal inspection. See 2.3.4. 



c) Structural Attachments 

The pressure vessel mountings should be 
checked for adequate allowance for expan- 
sion and contraction, such as provided by 
slotted bolt holes or un-obstructed saddle 
mountings. Attachments of legs, saddles, 
skirts, or other supports should be exam- 
ined for distortion or cracks at welds. 

d) Vessel Connections 

Components that are exterior to the vessel 
and are accessible without disassembly 
shall be inspected as described in this 
paragraph. Manholes, reinforcing plates, 
nozzles, couplings, or other connections 
shall be examined for cracks, deformation, 
or other defects. Bolts or nuts should be 
examined for corrosion or defects. Weep 
holes in reinforcing plates shall remain 



S7.6 



LEAKS 



Leakage is unacceptable. When leaks are iden- 
tified, the vessel shall be removed from service 
until repaired by a qualified repair organization 
or permanently removed from service. 



S7.7 



FIRE DAMAGE 



Vessels in which bulging exceeds the lim- 
its of S7.8.3 or distortion that exceeds the 
limits of the original code of construction 
(e.g., Section VIII, Div. 1 of the ASM E Boiler 
and Pressure Vessel Code) shal I be removed 
from service until repaired by a qualified re- 
pair organization or permanently removed 
from service. 



26D 



NATIONAL BOARD INSPECTION CODE • PART Z 



INSPECTION 



b) Common evidence of exposure to fire is: S7.8 



ACCEPTANCE CRITERIA 



1 ) charring or burning of the paint or other 
protective coat, 

2) burning or scarring of the metal, 

3) distortion, or 

4) burning or melting of the valves. 

c) A pressure vessel that has been subjected 
to the action of fire shall be removed from 
service until it has been properly evaluated. 
The general intent of this requirement is to 
remove from service pressure vessels which 
have been subject to the action of fire that 
has changed the metallurgical structure or 
the strength properties of the steel. Visual 
examination with emphasis given to the 
condition of the protective coating can be 
used to evaluate exposure from a fire. This 
is normally determined by visual exami- 
nation as described above with particular 
emphasis given to the condition of the 
protective coating. If there is evidence that 
the protective coating has been burned off 
any portion of the pressure vessel surface, 
or if the pressure vessel is burned, warped, 
or distorted, it is assumed that the pressure 
vessel has been overheated. If, however, 
the protective coating is only smudged, 
discolored, or blistered, and is found by 
examination to be intact underneath, the 
pressure vessel shall not be considered af- 
fected within the scope of this requirement. 
Vessels that have been involved in a fire 
and show no distortion shall be requalified 
for continued service by retesting using the 
hydrostatic test procedure applicable at the 
time of original fabrication. 

d) Subject to the acceptance of the Jurisdic- 
tion and the Inspector, alternate methods 
of pressure testing may be used. 



The acceptance criteria for LPG vessels is based 
on successfully passing inspections without 
showing conditions beyond the limits shown 
below. 



S7.8.1 



CRACKS 



Cracks in the pressure boundary (heads, shells, 
welds) are unacceptable. When a crack is iden- 
tified, the vessel shall be removed from service 
until the crack is repaired by a qualified repair 
organization or permanently retired from ser- 
vice. (See Part 3, Repairs and Alterations). 



S7.8.2 



DENTS 



a) Shells 

The maximum mean dent diameter in shells 
shall not exceed 10% of the shell diameter, 
and the maximum depth of the dent shall 
not exceed 1 0% of the mean dent diameter. 
The mean dent diameter is defined as the 
average of the maximum dent diameter and 
the minimum dent diameter. If any portion 
of the dent is closer to a weld than 5% of 
the shel I diameter, the dent shal I be treated 
as a dent in a weld area, see (b) below. 

b) Welds 

The maximum mean dent diameter on 
welds (i.e., part of the deformation includes 
a weld) shall not exceed 1 0% of the shell 
diameter. The maximum depth shall not 
exceed one twentieth of the mean dent 
diameter. 

c) Heads 

The maximum mean dent diameter on 
heads shall not exceed 10% of the shell 
diameter. The maximum depth shall not 
exceed one twentieth of the mean dent 
diameter. The use of a template may be 
required to measure dents on heads. 



26 l 



NATIONAL BOARD INSPECTION CODE • PART 2 



INSPECTION 



d) When dents are identified that exceed the 
limits set forth in these paragraphs, the 
vessel shall be removed from service until 
the dents are repaired by a qualified repair 
organization or permanently retired from 
service. 



S7.8.5 



CORROSION 



S7.8.3 



BULGES 



a) Shells 

If a bulge is suspected, the circumference 
shall be measured at the suspect location 
and several places remote from the suspect 
location. The variation between measure- 
ments shall not exceed 1 %. 

b) Heads 

1) If a bulge is suspected, the radius of 
curvature shall be measured by the use 
of templates. At any point the radius 
of curvature shall not exceed 1 .25% of 
the diameter for the specified shape of 
the head. 

2) When bulges are identified that exceed 
the limits set forth in these paragraphs, 
the vessel shall be removed from ser- 
vice until the bulges are repaired by a 
qualified repair organization or perma- 
nently retired from service. 



S7.8.4 



CUTS OR GOUGES 



When a cut or a gouge exceeds 1/4 of the thick- 
ness of the vessel, the vessel shall be removed 
from service until it is repaired by a qualified 
repair organization or permanently removed 
from service. 



a) Line and Crevice Corrosion 

For line and crevice corrosion, the depth 
of the corrosion shall not exceed 1/4 of the 
original wall thickness. 

b) Isolated Pitting 

Isolated pits may be disregarded provided 
that: 

1) Their depth is not more than one-half 
the required thickness of the pressure 
vessel wall (exclusive of corrosion al- 
lowance); 

2) The total area of the pits does not ex- 
ceed 7 sq. in. (4500 sq. mm) within any 
8 in. (200 mm) diameter circle; and 

3) The sum of their dimensions along any 
straight line within this circle does not 
exceed 2 in. (50 mm). 

c) General Corrosion 

For a corroded area of considerable size, 
the thickness along the most critical plane 
of such area may be averaged over a length 
not exceeding 20 in. (500 mm). The thick- 
ness at the thinnest point shall not be less 
than 50% of the required wall thickness, 
and the average shall not be less than 
75% of the required wall thickness. When 
general corrosion is identified that exceeds 
the limits set forth in this paragraph, the 
pressure vessel shall be removed from 
service until it is repaired by a qualified 
organization or permanently removed from 
service. 



262 



Insert 

Section 7 
Tab 

Here 




Part 2, Sects on V 
Inspection — NBIC Policy 
For Metrication 



263 



NATIONAL BOARD INSPECTION CODE ° PART 2 



INSPECTION 



PART 2, SECTION 7 
INSPECTION — NBIC POLICY FOR METRICATION 



7.1 



GENERAL 



This policy provides guidance for the use of 
US customary units and metric units. Through- 
out the NBIC, metric units are identified and 
placed in parentheses after the US customary 
units referenced in the text and associated 
tables. For each repair or alteration performed, 
selection of units shall be based on the units 
used in the original code of construction. For 
example, items constructed using US custom- 
ary units shall be repaired or altered using US 
customary units. The same example applies to 
items constructed using metric units. Which- 
ever units are selected, those units are to be 
used consistently throughout each repair or 
alteration. Consistent use of units includes all 
aspects of work required for repairs or altera- 
tions (i.e. materials, design, procedures, testing, 
documentation, and stamping, etc.). 



7.2 



EQUIVALENT RATIONALE 



The rationale taken to convert metric units 
and US customary units involves knowing the 
difference between a soft conversion and a 
hard conversion. A soft conversion is an exact 
conversion. A hard conversion is simply per- 
forming a soft conversion and then rounding 
off within a range of intended precision. When 
values specified in the NBIC are intended to 
be approximate values, a hard conversion is 
provided. If an exact value is needed to main- 
tain safety or required based on using good 
engineering judgment, then a soft conversion 
will be used. In general, approximate accuracy 
is acceptable for most repairs or alterations 
performed using the requirements of the NBIC. 
Therefore, within the NBIC, metric equivalent 
units are primarily hard conversions. 



The following examples are provided for further 
clarification and understanding of soft conver- 
sions versus hard conversions: 

Example 1 : Using 1 in. - 25 .4 mm; 
12 in. = 304.8 mm (soft conversion) 

Example 2: Using the above conversion, a hard 
conversion may be 300 mm or 305 mm de- 
pending on the degree of precision needed. 



7.3 PROCEDURE FOR 

CONVERSION 

The following guidelines shall be used to con- 
vert between US customary units and metric 
units within the text of the NBIC: 

a) All US customary units will be converted 
using a soft conversion. 

b) Soft conversion calculations will be re- 
viewed for accuracy. 

c) Based on specified value in the NBIC, an 
appropriate degree of precision shall be 
identified. 

d) Once the degree of precision is decided, 
rounding up or down may be applied to 
each soft conversion in order to obtain a 
hard conversion. 

e) Use of hard conversion units shall be used 
consistently throughout the NBIC wherever 
soft conversions are not required. 

Note: Care shall be taken to minimize 
percentage difference between units. 



264 



NATIONAL BOARD INSPECTION CODE • PART Z — INSPECTION 



7.4 



REFERENCING TABLES 



The following tables are provided for guidance 
and convenience when converting between US 
customary units and metric units. See Tables 
7.4-1 through 7.4-8. 

Temperature shall be converted to within 1°C 
as shown in Table 7.4-2 



TABLE 7.4-1 

Soft Conversion Factors 

(US x Factor = Metric) 


US Customary 


Metric 


Factor 


in. 


mm 


25.4 


ft. 


m 


0.3048 


in. 2 


mm 2 


645.16 


ft. 2 


m 2 


0.09290304 


in. 3 


mm 3 


16,387.064 


ft. 3 


m 3 


0.02831685 


US gal. 


m 3 


0.003785412 


US gal. 


liters 


3.785412 


psi 


MPa 


0.0068948 


psi 


kPa 


6.894757 


ft-lb 


J 


1.355818 


°F 


°C 


5/9 x (°F-32) 


R 


K 


5/9 


Ibm 


kg 


0.4535924 


Ibf 


N 


4.448222 


in.-lb 


N-mm 


112.98484 


ft.-lb 


N-m 


1.3558181 


ksiVin 


MPaVm 


1.0988434 


Btu/hr 


W 


0.2930711 


lb/ft 3 


kg/m 3 


16.018463 


in.-wc 


kPa 


0.249089 


Note: The actual pre 
of a vertical columr 
gravitational field a 
in turn depends upc 
sion factor is the co 
The conversion assi 
(g n - 9.80665 N/kg) 
1 ,000 kg/m 3 . 


assure corresp 
of fluid depe 
id the density 
m the temper 
nventional va 
mes a standa 
and a density 


>onding to the height 
>nds on the local 
of the fluid, which 
ature. This conver- 
ge adopted by ISO. 
rd gravitational field 
' of water equal to 



Fractions of an inch shall be converted accord- 
ing to Table 7.4-3. Even increments of inches 
are in even multiples of 25 mm. For example, 
40 inches is equivalent to 1000 mm. Interme- 
diate values may be interpolated rather than 
converting and rounding to the nearest mm. 

For nominal pipe sizes, the following relation- 
ships were used as shown in Table 7.4-4. 

Areas in square inches (in 2 ) were converted 
to square mm (mm 2 ) and areas in square feet 
(ft 2 ) were converted to square meters (m 2 ). See 
examples in Tables 7.4-5a and 7.4-5b. 

Volumes in cubic inches (in. 3 ) were converted 
to cubic mm (mm 3 ) and volumes in cubic feet 
(ft 3 ) were converted to cubic meters (m 3 ). See 
examples in Tables 7.4-6a and 7.4-6b. 

Although the pressure should always be in MPa 
for calculations, there are cases where other 
units are used in the text. For example, kPa is 
used for small pressures. Also, rounding was to 
two significant figures. See examples in Table 
7.4-7. (Note that 1 4.7 psi converts to 1 01 kPa, 
while 15 psi converts to 100 kPa. While this 
may seem at first glance to be an anomaly, it is 
consistent with the rounding philosophy.) 

Material properties that are expressed in psi 
or ksi (e.g., allowable stress, yield and tensile 



TABLE 7.4-2 
Temperature Equivalents 


Temperature °F 


Temperature °C 


60 


16 


70 


21 


100 


38 


120 


49 


350 


177 


400 


204 


450 


232 


800 


427 


1150 


621 





265 



NATIONAL BOARD INSPECTION CODE " PART 2 



INSPECTION 



strength, elastic modulus) were generally con- 
verted to MPa to three significant figures. See 
example in Table 7.4-8. 

An often seen metric pressure rating is the ex- 
pression BAR, one BAR equals 14.5 psi — to 
convert psi rating to a BAR rating, multiply by 
0.069. 



TABLE 7.4-3 

US Fractions/Metric Equivalents 




Inches 


Millimeters 




1/32 


0.8 


3/64 


1.2 


1/16 


1.5 


3/32 


2.5 


1/8 


3 


5/32 


4 


3/16 


5 


7/32 


5.5 


1/4 


6 


5/16 


8 


3/8 


10 


7/16 


11 


1/2 


13 


9/16 


14 


5/8 


16 


11/16 


17 


3/4 


19 


7/8 


22 


1 


25 









TABLE 7.4-4 

Pipe Sizes/Equivalents 




US Customary 
Practice 


Metric Practice 




NPS 1/8 


DN 6 


NPS 1/4 


DN 8 


NPS 3/8 


DN 10 


NPS 1/2 


DN 15 


NPS 3/4 


DN 20 


NPS 1 


DN25 


NPS 1-1/4 


DN32 


NPS 1-1/2 


DN40 


NPS 2 


DN50 


NPS 2-1/2 


DN 65 


NPS 3 


DN 80 


NPS 3-1/2 


DN90 


NPS 4 


DN 100 


NPS 5 


DN 125 


NPS 6 


DN 150 


NPS 8 


DN200 


NPS 10 


DN250 


NPS 12 


DN300 


NPS 14 


DN350 


NPS 16 


DN400 


NPS 18 


DN450 


NPS 20 


DN 500 


NPS 22 


DN550 


NPS 24 


DN600 


NPS 26 


DN 650 


NPS 28 


DN 700 


NPS 30 


DN 750 


NPS 32 


DN 800 


NPS 34 


DN 850 


NPS 36 


DN900 


NPS 38 


DN950 


NPS 40 


DN 1000 


NPS 42 


DN 1050 


NPS 44 


DN 1100 


NPS 46 


DN 1150 


NPS 48 


DN 1200 


NPS 50 


DN 1250 


NPS 52 


DN 1300 


NPS 54 


DN 1350 


NPS 56 


DN 1400 


NPS 58 


DN 1450 


NPS 60 


DN 1500 





266 



NATIONAL BOARD INSPECTION CODE • PART 2 



INSPECTION 



Table 7.4-5a 



Area (US Customary) 


Area (Metric) 


3 in 2 


650 mm 2 


6 in 2 


3,900 mm 2 


10 in 2 


6,500 mm 2 



Tab!e 7.4-5b 



Table 7.4-6a 



Table 7.4-6b 



Area (US Customary) 


Area (Metric) 


5 ft 2 


0.46 mm 2 



Area (US Customary) 


Area (Metric) 


1 in 3 


1 6,000 mm 3 


6 in 3 


96,000 mm 3 


10 in 5 


160,000 mm 3 



Area (US Customary) 


Area (Metric) 


5 ft 3 


0.14 m 3 



TABLE 7.4-7 
Pressure/Equivalents 


Pressure (US Customary) 


Pressure (Metric) 


0.5 psi 


3 kPa 


2 psi 


15 kPa 


3 psi 


20kPa 


10 psi 


70 kPa 


15 psi 


1 00 kPa 


30 psi 


200 kPa 


50 psi 


350 kPa 


100 psi 


700 kPa 


150 psi 


1 .03 MPa 


200 psi 


1.38 MPa 


250 psi 


1 .72 MPa 


300 psi 


2.10 MPa 


350 psi 


2.40 MPa 


400 psi 


2.76 MPa 


500 psi 


3.45 MPa 


600 psi 


4.14 MPa 


1,200 psi 


8.27 MPa 


1,500 psi 


10.34 MPa 






Table 7.4-8 


Strength (US Customary) 


Strength (Metric) 


95,000 psi 


655 MPa 





267 



NATIONAL BOARD INSPECTION CODE • PART Z 



INSPECTION 



2SS 



1 i ^F I B 

©. * te 9 H jP i ! (I 

ab 

■ in s m^- h isr^ ■' 




Part 2, Section B 
Inspection — Preparation df 
Technical Inquiries to the National 
Board Inspection Code Committee 



269 



NATIONAL BOARD INSPECTION CODE • PART Z 



INSPECTION 



PART 2, SECTION H 

INSPECTION — PREPARATION OF TECHNICAL INQUIRIES TO 

THE NATIONAL BOARD INSPECTION CODE COMMITTEE 



8.1 



INTRODUCTION 



The NBIC Committee meets regularly to con- 
sider written requests for interpretations and 
revisions to the Code rules. This section pro- 
vides guidance to Code users for submitting 
technical inquiries to the Committee. Technical 
inquires include requests for additions to the 
Code rules and requests for Code Interpreta- 
tions, as described below. 

a) Code Revisions 

Code revisions are considered to accommo- 
date technological developments, address 
administrative requirements, or to clarify 
Code intent. 

b) Code Interpretations 

Code Interpretations provide clarification of 
the meaning of existing rules in the Code, 
and are also presented in question and re- 
ply format. Interpretations do not introduce 
new requirements. In cases where existing 
Code text does not fully convey the mean- 
ing that was intended, and revision of the 
rules is required to support an Interpreta- 
tion, an intent Interpretation will be issued 
and the Code will be revised. As a matter of 
published policy, the National Board does 
not approve, certify, or endorse any item, 
construction, propriety device or activity 
and, accordingly, inquiries requiring such 
consideration will be returned. Moreover, 
the National Board does not act as a con- 
sultant on specific engineering problems or 
on the general application or understanding 
of the Code rules. 

Inquiries that do not comply with the provi- 
sions of this Section or that do not provide 
sufficient information for the Committee's 



full understanding may result in the request 
being returned to the inquirer with no ac- 
tion. 



8.2 INQUIRY FORMAT 

Inquiries submitted to the Committee shall 
include: 

a) Purpose 

Specify one of the following: 

1 ) revision of present Code rules; 

2) new or additional Code rules; or 

3) Code Interpretation. 

b) Background 

Provide concisely the information needed 
for the Committee's understanding of the 
inquiry, being sure to include reference 
to the applicable Code Edition, Addenda, 
paragraphs, figures, and tables. Preferably, 
provide a copy of the specific referenced 
portions of the Code. 

c) Presentations 

The inquirer may attend a meeting of the 
Committee to make a formal presentation 
or to answer questions from the Committee 
members with regard to the inquiry. Atten- 
dance at a Committee meeting shall be at 
the expense of the inquirer. The inquirer's 
attendance or lack of attendance at a meet- 
ing shall not be a basis for acceptance or 
rejection of the inquiry by the Committee. 



27D 



NATIONAL BOARD INSPECTION CODE • PART Z — INSPECTION 



8.3 CODE REVISIONS OR 

ADDITIONS 

Request for Code revisions or additions shall 
provide the following: 

a) Proposed Revisions or Additions 

For revisions, identify the rules of the Code 
that require revision and submit a copy 
of the appropriate rules as they appear in 
the Code, marked up with the proposed 
revision. For additions, provide the recom- 
mended wording referenced to the existing 
Code rules. 

b) Statement of Need 

Provide a brief explanation of the need for 
the revision or addition. 

c) Background Information 

Provide background information to support 
the revision or addition, including any data 
or changes in technology that form the basis 
for the request that will allow the Commit- 
tee to adequately evaluate the proposed 
revision or addition. Sketches, tables, fig- 
ures, and graphs should be submitted as 
appropriate. When applicable, identify any 
pertinent paragraph in the Code that would 
be affected by the revision or addition and 
identify paragraphs in the Code that refer- 
ence the paragraphs that are to be revised 
or added. 



8.4 CODE INTERPRETATIONS 

Requests for Code Interpretations shall provide 
the following: 

a) Inquiry 

Provide a condensed and precise question, 
omitting superfluous background informa- 
tion and, when possible, composed in such 
a way that a "yes" or a "no" reply, with brief 
provisos if needed, is acceptable. The ques- 
tion should be technically and editorially 
correct. 



b) Reply 

Provide a proposed reply that will clearly 
and concisely answer the inquiry question. 
Preferably the reply should be "yes" or "no" 
with brief provisos, if needed. 

c) Background Information 

Provide any background information that 
will assist the Committee in understanding 
the proposed Inquiry and Reply Requests 
for Code Interpretations must be limited to 
an interpretation of the particular require- 
ment in the Code. The Committee cannot 
consider consulting type requests such as: 

1 ) A review of calculations, design draw- 
ings, welding qualifications, or descrip- 
tions of equipment or Parts to determine 
compliance with Code requirements; 

2) A request for assistance in performing 
any Code-prescribed functions relating 
to, but not limited to, material selec- 
tion, designs, calculations, fabrication, 
inspection, pressure testing, or installa- 
tion; 

3) A request seeking the rationale for Code 
requirements. 



8.5 SUBMITTALS 

Submittals to and responses from the Commit- 
tee shall meet the following: 

a) Submittal 

Inquiries from Code users shall be in English 
and preferably be submitted in typewritten 
form; however, legible handwritten inqui- 
ries will be considered. They shall include 
the name, address, telephone number, fax 
number, and email address, if available, of 
the inquirer and be mailed to the following 
address: 

Secretary, NBIC Committee 
The National Board of Boiler and 

Pressure Vessel Inspectors 
1055 Crupper Avenue 
Columbus, OH 43229 



27 1 



NATIDNAL BDARD INSPECTION CDDE • PART 2 — INSPECTION 

As an alternative, inquiries may be submit- 
ted via fax or email to: 

Secretary NBIC Committee 

Fax: 614.847.1828 

Email: NBICinquiry@nationalboard.org 

b) Response 

The Secretary of the NBIC Committee shall 
acknowledge receipt of each properly pre- 
pared inquiry and shall provide a written 
response to the Inquirer upon completion 
of the requested action by the NBIC Com- 
mittee. 



ZV2 



Insert 

Section 9 
Tab 

Here 




Part 2, Section <3 

Inspection — Glossary of Terms 



273 



NATIONAL BOARD INSPECTION CODE • PART Z 



INSPECTION 



PART 2 f SECTION 9 
INSPECTION — GLOSSARY OF TEW 



9.1 



DEFINITIONS 



For the purpose of applying the rules of the 
NBIC, the following terms and definitions shall 
be used herein as applicable to each Part: 

Additional terms and definitions specific to 
DOT Transport Tanks are defined in Part 2, 
Supplement 6. 

Accumulator — A vessel in which the test 
medium is stored or accumulated prior to its 
use for testing. 

Alteration — Any change in the item described 
on the original Manufacturer's Data Report that 
affects the pressure containing capability of the 
pressure-retaining item. Nonphysical changes 
such as an increase in the maximum allowable 
working pressure (internal or external), increase 
in design temperature, or a reduction in mini- 
mum temperature of a pressure-retaining item 
shall be considered an alteration. 

ANSI — The American National Standards 
Institute 

ASME Code — The American Society of Me- 
chanical Engineers' Boiler and Pressure Vessel 
Code published by that Society, including 
addenda and Code Cases, approved by the 
associated ASME Board. 

Assembler — An organization who purchases 
or receives from a manufacturer the necessary 
component parts of valves and assembles, 
adjusts, tests, seals, and ships safety or safety 
relief valves at a geographical location, and 
using facilities other than those used by the 
manufacturer. 

Authorized Inspection Agency — 

New Construction: An Authorized Inspec- 
tion Agency is one that is accredited by the 



National Board meeting the qualification 
and duties of NB-360, Criteria for Accep- 
tance of Authorized Inspection Agencies 
for New Construction. 

Inservice: An Authorized Inspection Agency 
is either: 

a) a jurisdictional authority as defined in 
the National Board Constitution; or 

b) an entity that is accredited by the Na- 
tional Board meeting NB 369, Quali- 
fications and Duties for Authorized 
Inspection Agencies Performing Inser- 
vice Inspection Activities and Quali- 
fications for Inspectors of Boilers and 
Pressure Vessels; NB-371 , Accreditation 
of Owner-User Inspection Organiza- 
tions (OUIO) or NB-390, For Federal 
Inspection Agencies (FIAs) Performing 
Inservice Inspection Activities. 

Capacity Certification — The verification by the 
National Board that a particular valve design or 
model has successfully completed all capacity 
testing as required by the ASME Code. 

Chimney or Stack — A device or means for 
providing the venting or escape of combustion 
gases from the operating unit. 

Conversion — 

Pressure Relief Devices: The change of a pres- 
sure relief valve from one capacity-certified 
configuration to another by use of manufac- 
turer's instructions. 

Units of Measure: Changing the numeric value 
of a parameter from one system of units to 
another. 

Demonstration — A program of making evident 
by illustration, explanation, and completion of 
tasks documenting evaluation of an applicant's 



274 



NATIDNAL BOARD INSPECTION CODE • PART Z 



INSPECTION 



ability to perform code activities, including the 
adequacy of the applicant's quality program, 
and by a review of the implementation of that 
program at the address of record and/or work 
location. 

Dutchman — Generally limited to tube or pipe 
cross-section replacement. The work necessary 
to remove a compromised section of material 
and replace the section with material meet- 
ing the service requirements and installation 
procedures acceptable to the Inspector. Also 
recognized as piecing. 

Examination — In process work denoting the 
act of performing or completing a task of inter- 
rogation of compliance. Visual observations, 
radiography, liquid penetrant, magnetic par- 
ticle, and ultrasonic methods are recognized 
examples of examination techniques. 

Exit — A doorway, hallway, or similar passage 
that will allow free, normally upright unencum- 
bered egress from an area. 

Field — A temporary location, under the control 
of the Certificate Holder, that is used for repairs 
and/or alterations to pressure-retaining items at 
an address different from that shown on the Cer- 
tificate Holder's Certificate of Authorization. 

Forced- Flow Steam Generator — A steam gen- 
erator with no fixed steamline and waterline. 

Inspection — A process of review to assure 
engineering design, materials, assembly, ex- 
amination and testing requirements have been 
met and are compliant with the Code. 

Inspector — See National Board Commis- 
sioned Inspector and National Board Owner- 
User Commissioned Inspector. 

Intervening — Coming between or inserted 
between, as between the test vessel and the 
valve being tested. 



Jurisdiction — A governmental entity with 
the power, right, or authority to interpret and 
enforce law, rules, or ordinances pertaining 
to boilers, pressure vessels, or other pressure- 
retaining items. It includes National Board 
member jurisdictions defined as "jurisdictional 
authorities". 

Jurisdictional Authority — A member of the 
National Board, as defined in the National 
Board Constitution. 

Lift Assist Device — A device used to apply an 
auxiliary load to a pressure relief valve stem or 
spindle, used to determine the valve set pres- 
sure as an alternative to a full pressure test. 

Manufacturer's Documentation — The docu- 
mentation that includes technical information 
and certification required by the original code 
of construction. 

NBIC — The National Board Inspection Code 
published by The National Board of Boiler and 
Pressure Vessel Inspectors. 

"NR" Certificate Holder — An organization in 
possession of a valid "NR" Certificate of Autho- 
rization issued by the National Board. 

National Board — The National Board of Boiler 
and Pressure Vessel Inspectors. 

National Board Commissioned Inspector — An 

individual who holds a valid and current Na- 
tional Board Commission. 

Nuclear Items — Items constructed in accor- 
dance with recognized standards to be used 
in nuclear power plants or fuel processing 
facilities. 

Original Code of Construction — Documents 
promulgated by recognized national standards 
writing bodies that contain technical require- 
ments for construction of pressure-retaining 
items or equivalent to which the pressure- 
retaining item was certified by the original 
manufacturer. 



275 



NATIONAL BOARD INSPECTION CODE • PART 2 — INSPECTION 



Owner or User — As referenced in lower case 
letters means any person, firm or corporation 
legal ly responsible for the safe operation of any 
pressure-retaining item. 

Owner-User Inspection Organization — An 
owner or user of pressure-retaining items that 
maintains an established inspection program, 
whose organization and inspection procedures 
meet the requirements of the National Board 
rules and are acceptable to the jurisdiction or 
jurisdictional authority wherein the owner or 
user is located. 

Owner-User Inspector — An individual who 
holds a valid and current National Board 
Owner-User Commission. 

Piecing — A repair method used to remove 
and replace a portion of piping or tubing ma- 
terial with a suitable material and installation 
procedure. 

Pressure-Retaining Items (PR!) — Any boiler, 
pressure vessel, piping, or material used for 
the containment of pressure, either internal or 
external. The pressure may be obtained from 
an external source, or by the application of 
heat from a direct source, or any combination 
thereof. 



Re-rating — See alteration. 

"W Certificate Holder — An organization in 
possession of a valid "R" Certificate of Autho- 
rization issued by the National Board. 

Safety Relief Valves — A safety relief valve is 
a pressure relief valve characterized by rapid 
opening or pop action, or by opening in propor- 
tion to the increase in pressure over the opening 
pressure, depending on application. 

Settings — Those components and accessories 
required to provide support for the component 
during operation and during any related main- 
tenance activity. 

Shop — A permanent location, the address that 
is shown on the Certificate of Authorization, 
from which a Certificate Holder controls the 
repair and/or alteration of pressure-retaining 
items. 

Testing Laboratory — National Board accepted 
laboratory that performs functional and capac- 
ity tests of pressure relief devices. 

Transient — An occurrence that is maintained 
only for a short interval as opposed to a steady 
state condition. 



Pressure Test — Prior to initial operation, the 
completed boiler, including pressure piping, 
water columns, superheaters, economizers, 
stop valves, etc., shall be pressure tested in a 
test performed in accordance with the original 
code of construction prior to initial operation 
of an installed unit that is witnessed by an 
Inspector. 

Repair — The work necessary to restore pres- 
sure-retaining items to a safe and satisfactory 
operating condition. 

Re-ending — A method used to join original 
code of construction piping or tubing with 
replacement piping or tubing material for the 
purpose of restoring a required dimension, 
configuration or pressure-retaining capacity. 



Velocity Distortion — The pressure decrease 
that occurs when fluid-flows past the opening 
of a pressure sensing line. This is a distortion 
of the pressure that would be measured under 
the same conditions for a non or slowly mov- 
ing fluid. 

"VR" Certificate Holder — An organization in 
possession of a valid "VR" Certificate of Autho- 
rization issued by the National Board. 

Water Head — The pressure adjustment that 
must be taken into account due to the weight 
of test media (in this case, water) that is 0.433 
psi per vertical ft. (1 kPa per m.) added (sub- 
tracted) from the gage pressure for each foot 
the gage is below (above) the point at which 
the pressure is to be measured. 



276 



li 



Insert 

Section 10 
Tab 

Here 




HU 



^ 



^ 



■:, 




Part 2, Section 1 D 
Inspection — NBIC-Apprdved 

Interpretations 



277 



NATIONAL BOARD INSPECTION CODE • PART Z 



INSPECTION 



PART 2, SECTION 10 
INSPECTION — NBIC APPROVED INTERPRETATIONS 



10.1 



SCOPE 



This section provides all approved interpre- 
tations for this edition and all subsequent 
addenda associated with this edition. A 
complete listed index is provided for refer- 
ence to previously approved interpretations. 
These previously approved interpretations 
can be found on the National Board Web 
site. 



b) Each interpretation references the edition 
and addenda applicable at the time of 
committee response and approval. Use of 
interpretations for other than approved edi- 
tion and addenda may not be appropriate 
for reference. 



10.2 INDEX OF INTERPRETATIONS 

Foreword 95-20 

Code Cases 1923 98-24 

98-56 

1945 98-24 

98-56 

2203 98-12 

Procedure for Obtaining or Renewing a National Board 

Certificate of Authorization 98-21 

Outline of Requirements for a Quality System 

for Qualification for the National Board "R" Symbol Stamp 98-13 

General Rules 04-02 

Condition of Use 98-02 

Nameplate Contents 98-25 

98-26 
95-26 

Use of Owner-User Personnel During Repairs 01-12 

Test Medium and Testing Equipment 98-17 

Procedure for Obtaining or Renewing a National Board 

"NR" Certificate of Authorization 98-07 

98-41 

Interface with the Owner's Repair/Replacement Program 04-16 

Prerequisites for Accreditation 98-16 

General Conditions 98-11 

Pressure Testing 95-38 

Inspection Interval 98-19 

Conditions that Affect Remaining Life Evaluation 01-26 

98-03 
95-57 

Operational Inspection 95-55 

Inspection of Parts and Appurtenances 98-09 



27B 



NATIONAL BOARD INSPECTION CODE • PART 2 — INSPECTION 



Restamping or Replacement of Nameplates 98-35 

95-47 

Replacement of Stamped Data 01-13 

General Requirements 04-14 

95-19 

Scope 98-22 

Construction Standard 95-36 

95-48 
04-1 3 

Accreditation 04-13 

Materials 01-28 

Replacement Parts 04-05 

04-06 
04-11 
04-12 
98-14 
98-27 
98-28 
98-37 
95-48 

Welding 01-27 

98-06 
95-51 

Nondestructive Examination 04-06 

01-24 
98-10 
95-41 

Acceptance Inspection 04-21 

04-22 

Routine Repairs 04-09 

04-10 
01-19 
01-20 
01-22 
01-23 
98-01 
98-04 
98-18 
98-31 
98-42 
95-27 
95-28 
95-31 
95-33 
95-53 

Examination and Test 04-05 

04-06 
04-11 
98-27 
98-33 
98-36 
95-27 
95-32 
95-39 
95-54 

279 



NATIDNAL BOARD INSPECTION CODE • PART Z — INSPECTION 



Methods 04-06 

04-11 

04-20 

01-15 
Documentation 01-29 

95-50 
Repair Plan 01-14 

Alterations to ASME Section VIII, Div. 2 04-14 

01-16 
Design 98 _ 14 

95-22 
04-13 

Calculations 01-1 7 

Re-Rating 04-03 

04-04 
01-11 
98-14 
98-15 
98-20 
98-32 
Examination and Test 98-15 

98-34 
98-38 

Methods 04-20 

Documentation 01-25 

95-50 

Repair Methods 04-01 

Scope 98-06 

Welding Method 1 04-12 

Scope 04-17 

04-19 
98-08 

Wasted Areas 98-42 

Re-Ending or Piecing Pipes or Tubes 98-36 

Patches 04-15 

95-52 

Stays 98-40 

Re-Rating 04-18 

Replacement Parts 04-07 

04-08 

Stamping and Nameplate Information 95-24 

Glossary of Terms 04-13 

95-21 
95-29 
95-34 
95-43 

95-45 
National Board Forms 98-39 

95-25 
95-30 
95-40 
95-42 



2SD 



NATIONAL BOARD INSPECTION CODE • PART 2 — INSPECTION 



Examples of Repairs and Alterations 01-21 

98-23 
98-29 
98-30 
95-44 
95-46 
95-48 
95-49 

Repairs 01-18 



ZB 1 



NATIDNAL BOARD INSPECTION CODE • PART 2 — INSPECTION 



10.3 SUBJECT INDEX OF INTERPRETATIONS 

Acceptance Inspection 04-13 

04-21 
04-22 

Alteration Requirements 04-14 

Alterations to ASME Section VIII, Div. 2 01-16 

Alternatives to PWHT 98-06 

Attachments 98-01 

Blisters, Repair of 98-09 

Calculations 01-1 7 

Construction Standards 04-13 

Deaerators, Inspection of 98-09 

Defect Repairs 04-1 7 

04-19 

Definition of Repair 98-23 

98-29 
98-30 
95-43 
95-45 
95-46 
95-49 

Definition of Alteration 95-21 

95-36 
95-44 
95-45 

Definition of Inspector 95-29 

Definition of Non-Load Bearing 95-33 

Demonstration Requirements 98-41 

De-Rating 98-20 

Design 04-13 

Deterioration 01-26 

Documentation 01-25 

95-50 

Examination and Test 04-05 

04-06 
04-11 
04-20 

Examples of Repairs and Alterations 01-21 

General Rules 04-02 

04-14 

Inspection Interval 98-19 

95-57 

Joint Review Demonstration Requirements 98-21 

Material Thickness 98-36 

Materials 01-28 

MTR 98-37 

Nameplates 95-24 

Non "U" Stamped Vessels 95-23 

Nondestructive Examination 04-06 

01-24 
98-10 

Nuclear Components 98-07 

Original Code of Construction 95-19 



zsz 



NATIONAL BOARD INSPECTION CDDE • PART 2 — INSPECTION 

Out-of-Service 98-03 

Owner-User Inspection 98-1 1 

98-16 

Owner's Repair/Replacement Program 04-16 

Patches 04-15 

Pi P in g 98-22 

Pressure Relief Valves 98-02 

98-1 3 
98-17 
98-24 
98-25 
98-26 
95-26 
95-55 
95-56 
Pressure Testing 98-15 

98-27 
98-33 
98-34 
98-38 
95-27 
95-32 
95-39 
95-38 

Pressure Testing Repairs 01-15 

Qualification of Welders/Welding Procedures 95-51 

Quality System Manual 98-13 

" R " Forms Z... 98-39 

95-27 
95-28 
95-30 
95-40 
95-42 
95-48 

95-50 
Repair Definition 04-13 

Repair Methods 04-01 

Re P airs ZZZZZZ.o^-^8 

Repair Plan 01-14 

Reclassification .....95-22 

Replacement Nameplates 98-35 

95-47 
Replacement Parts 04-05 

04-06 
04-07 
04-08 
04-11 
04-12 
98-14 
98-27 
98-28 
01-29 
Replacement of Stamped Data 01-13 

Re-Rating ZZZZZZZ...04-03 

04-04 

2B3 



NATIONAL BOARD INSPECTION CODE • PART 2 — INSPECTION 



04-18 

01-11 

98-14 

98-15 

\Z'".Z". 98-32 

Routine Repairs 04-09 

04-10 

01-19 

01-20 

01-22 

01-23 

98-1 

98-4 

98-18 

98-31 

98-42 

95-25 

95-27 

95-28 

95-31 

95-53 

95-54 

Stays Z 95-40 

Timing of Repairs 98-5 

95-41 

Use of Editions/Addenda 95-20 

Use of Owner/User Personnel During Repairs 01-12 

Welding 01-27 

Welding Methods 04-° 6 

04-12 

Window Patch 95-52 



2S4 



Insert 

Section 11 
Tab 

Here 



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Biisl 
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Ssfs 



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■ 



mm 




mW€^ 



HI / 



Si 

8 

li^ SKMllllS 



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Part 2, Section 1 1 
Inspection — Index 



2S5 



NATIONAL BOARD INSPECTION CODE 



Addenda — 

Part 1, Part 2, and Part 3 (Introduction) 

Additional Requirements for Alterations — 
Part 3 (S4.17) 

Additional Requirements for Repairs — 

Part 3 (S4.16) 

Administrative Requirements — 
Part 3 (Section 1 ) 

Administrative Procedures 

"R"/"VR'7"NR" — 
Part 3 (1.6), (1.7), (1.8), (S9.2) 

Acceptance Criteria — 
Part 2 (S.7.8) 

Acceptance Inspection — 
Part 1 (2.10), (2.10.5), (3.10), (4.6); Part 2 
(S7.8); Part 3 (1 .3.2), (S4.14), (S6.13) 

Accreditation — 

Part 3 (1.5), (1.6), (1.7), (1.8), (S2.6),(S6.3) 

Acoustic Emission — 

Part 2 (4.2.8); Part 3 (S4.13) 

Programs — 

Part 1, Part 2, and Part 3 (Introduction) 



Allowable Stress Values — 
Part 3 (3.4.2) 

ASME Code, 

Replacement Parts — 

Part 3 (3.2.2) 

Section VIII Division 2 and 3 — 

Part 3 (3.3.5), (3.4.4) 

Application of NBIC — 
Part 1, Part 2, and Part 3 (Edition including 
Addendum), (Foreword), (Introduction) 

Appurtenances — 

Part 1 (2.4.4), (2.5.3), (2.10.1), (3.3.4), (3.5.3), 
(4.6), (5.2.2), (5.2.5), (5.2.7); Part 2 
(1.5.2), (2.2.10), (S2.9), (2.3.5), (S6.16) 

Assembler — 

Part 1 , Part 2, and Part 3 (Section 9); Part 3 

(S7.5), (S7.6) 

Damage Mechanisms — 

Part 2 (3.1 .b) (4.4.6) 

Audit — 

Part 3 (1 .8.5.1 (q)), (S7.8) 

American National Standards Institute 
(ANSI) — 

Part 1 , Part 2, and Part 3 (Title Page), 
(Section 9) 



Adjustments, 
Alteration — 

Part 1 and Part 2 (Section 9); Part 3 (3.4), 
(3.4.4), (S3.4), (S4.1 7), (S5.7), (Section 9) 
Authorization of OwnerUsers — 
Part 3 (S7.10) 
Pressure Relief Valves — 
Part 3 (S7.2), (S7.6) 

Alternatives, 

Marking, Stamping — 
Part 3 (5.10) 

Nondestructive Examination — 
Parti (2.10.3), (S1.6); Part 3 (4.2) 
Postweld Heat Treatment — 
Part 3 (2.5.3), (S6.9.3) 
Verification Testing — 
Part 3 (1.7.5.5) 



American Petroleum Institute (API) — 
Part 2 (1 .3) 

Annual Review, "VR" — 
Part 3 (S7.11 .4) 

Arch Tube — 

Part 2 (S1 .4.2.1 7); Part 3 (SI .2.9.2) 

Ash Removal — 
Parti (2.6.2), (3.6.2) 

Authorization — 

Part 2 (5.2.1), (S6.4.6a)2)), (S6.5.1); 
Part 3 (1.3.1) 

Authorized Nuclear Inspector — 
Part 3 (1.8.5.1(0) 



2S6 



NATIONAL BOARD INSPECTION CODE 9 PART 2 — INSPECTION 



B_ 



Boilers — 

Part 2 (2.2), (2.5.5.1) 
Black Liquor — 
Part 2 (2.2.12.2) 
Cast Iron — 
Part 2 (2.2.12.5) 
Electric — 
Part 2 (2.2.12.6) 
Fired Coil Water Heaters — 
Part 2 (2.2.12.7) 

Fired Storage Water Heaters — 
Part 2 (2.2.12.8) 
Firetube — 
Part 2 (2.2.12.9) 
Historical — 

Part 2 (Supplement 2); Part 3 
(Supplement 2); 
Locomotive — 
Part 2 and 3 (Supplement 1 ) 
Modular — 
Parti (3.7.8) 
Thermal Fluid Heaters — 
Part 2 (2.2.12.3) 
Waste Heat — 
Part 2 (2.2.12.4) 
Watertube — 
Part 2 (2.2.12.1) 

Boiler Inspection Guideline (Historical) - 
Part 2 (S2.11) 

Boiler Installation, 

Heating/Potable Water Heaters — 

Part 1 (Section 3) 
Power Boilers — 

Part 1 (1 .4.5), (Section 2) 
Report — 

Parti (1.4.5), (2.10.6), (3.10.3) 
Steam Heating — 
Part 1 (Section 3) 

Boiler Operators (Historical) — 
Part 2 (S2 .4.3) 

Boiler Repair — 

Part 3 (3.3.4.2), (3.3.4.3), (Supplement 1), 
(Supplement 2) 



Boiler Relief Devices — 
Part 2 (2.5.5.1) 

Boiler Room Requirements — 
Part 1 (2.4), (3.4) 

Bonding — 
Part 3 (S4.10) 

Blowoff — 

Part 1 (2.7.5), (3.7.7); Part 2 (2.2.6 a)1), 
(5.3.4) 

Braces — 

Part 2 (S1 .4.2.6), (S1 .4.2.1 4), (S2.1 1 .6)k)); 

Part 3 (S1.2.6) 

Brittle Fracture — 

Part 2 ((3.4.4 a), (4.4.8.2 

Bulges and Blisters — 

Part 2 (2.2.8 j), (2.3.3 e) 5), (2.3.6.2), 

(2.3.6.4),(3.4.7), (4.4.8.3), (S7.8.3); Part 3 

(3.3.4.2) 

Burners and Stokers — 
Part 1 (2.7.2), (3.7.3); Part 2 (2.2.12), (S1.5.4), 
(S2.13.2) 



Calculations — 

Part 1 (7.3), (8.3); Part 2 (4.45), (S2.10.1), 
(S2.6.2), (Form C1) {73), (S5.2.1); Part 
3(3.2.4), (3.2.5), (3.4.1), (3.4.2), (7.3), 
(S1.1.4), (S4.6), (S4.16.3), (S4.17.4), 
(S4.17.5), (S4.18.2.3)(S.5.6.1), (S.5.6.2), 
(S6.7.1) 

Capacity — 

Part 1 (2.9.1.3), (5.3.4); Part 2 (2.3.6.2), 
(2.5.2), (2.5.4), (2.5.5.3), (2.5.7),(5.34), 
(5.35), (5.36), (Form C1), (S2.8.1), (S2.11; 
(S5.3.), (S6.8), , (S6.1 5.1), (S6. 15.4), 
(S6.16); Part 3 5.9.3 

Cargo Tanks — 

Part 2 (Supplement 6) 



237 



NATIONAL BOARD INSPECTION CODE 



Capacity Certification — 
Part 1 (5.3.1, (Section 9); Part 2 and Part 3 
(5.9.3), (Section 9) 

Caulking Riveted Seams — 

Part3 (S1 .2.12.1), (S2.13.13.1) 

Certificate of Authorization — 

Part 1 and Part 2 (Introduction); Part 3 

(Introduction), (1.6.2), (1.6.3), (1.7.6.5), 
(1.8.2), (1.8.3), (1.6.5.1) (1.7.1) (1.7.5) 
(1.7.6.7) (1.7.8) 

Certification — 

Part 1 (1 .4); Part 2 (4.2), (S.2.4), (S2.7.1 ), 
(S2.8.1), (S2.10.1), (S2.12), (S6.5.3), 
(S6.5.4.3), (S6.14.8); Part 3 (Section 5) 

Chimney or Stack — 
Parti (2.6.1), (3.6.1) 

Clearances — 

Part 1 (2.3.3), (3.3.4), (4.3.2) 

Cleaning — 

Parti (2.4.4), (5.2.7); Part 2 ((2.1), (S1.5.4), 
(S2.4.2), (S2.13.2), (S3.4) 

Codes and Standards — 
Part 2 (1.3), (4.5. 7),S2. 10.5), (S6.4.5), (S6.9); 
Part 3 (1 .2), (S2.5), (S3.2),(S4.7), (S6.2) 

Combustion Air — 

Parti (2.5.4), (3.5.4); Part 2 (2.2.4) 

Controls — 

Part 1 (2.5.3 d), (2.5.6),(2.8), (3.5.6), (3.8), 

(4.4); Part 2 (2.2.5),(2.2.10.7), (2.2.11), 

(2.2.12), (2.3.5.3), (2.4.8) 

Compressed Air Vessels — 
Part 2 (2.3.6.2) 

Condition of Installation — 
Part 2 (2.2.4), (2.3.2) 

Condensate — 

Part 1 (2.7.4) 



Connections — 

Part 1 (2.8.2.1), (3.7.6), (3.9.1.1.2), (3.9.4.3), 

(3.9.4.4); Part 2 (2.2.10), (2.3.3), (2.3.4), 

(2.3.6), (2.4.4), (2.4.5) 

Continued Service (DOT) — 
Part 2 (Supplement 6) 

Corrosion — 

Part 2 (2.2.8),(2.3.4), (Section 3), (S1.4.2), 
(S5.3.3), (S6.6), (S7.8.5); Part 3 (1.2), 
(3.3.3), (3.3.4.3), (3.4.2), (S2. 13.12.2), 
(S4.5), (S4.6), (S4.16.4), (S4.18), (S5.6.1), 

Control of Corrosion — 
Part 2 (3.3.3) 

Coatings — 

Part 2 (2.4.4), (2.5.5), (3.3.1), (3.3.3.4), 

Cracks — 

Part 2 (2.2.5), (2.2.9), (2.2.10), (2.2.12), 
(2.3.3), (2.3.4), (2.3.6), (3.3.2), (3.4), 
(3.4.9), (4.4), (S1.4.1), (S1.4.2), (S2.5.2), 
(S2.5.4), (S2.11), (S4.4.7), (S4.4.8), 
(S4.10), (S5.3.2), (S5.5), (S6.6.4), (S7.4), 
(S7.8.1); Part 3 (3.3.4.2), (S1 .2.10), 
(S1.2.11), (S2. 13.9.2), (S3.2), (S3. 5.3), 
(S2. 13.9.4), (S5.6.2) (Table S4.12), 
S4.1 8.2.2, S7.14.2 

Creep — 

Part 2 (3.1), (3.4.2), (3.4.7), (4.4.1), ((4.4.8.) 

Curing — 
Part 3 (S4.11) 

Cuts or Gouges — 

Part 2 (2.3.3), (2.4.4), (S1.4.2.3), (S1 .4.2.23), 
(S6.13.2),(S7.8.4); Part 3 (S7.14.2) 



Q. 



Damage Mechanisms — 
Part 2 (1.5), (2.3.2), (Section 3), (4.2.1), (4.4), 
(S2.5.2) 



2BS 



NATIONAL BOARD INSPECTION CODE • PART 2 — INSPECTION 



Deaerators — 

Parti (Section 10); Part 2 (2.3.6.1), 
(Section 10); Part 3 (Section 10) 

Defect Repairs — 
Part 3 (3.3.1), (3.3.4.2) 

Definitions — 

Part 1 (2.2), (3.2), (4.2)(Section 9); Part 2 
(4.5.2), (S6.16), (Section 9); Part 3 (1.4), 
(Section 9) 

Definition Relating to Pressure Relief 
Devices — 
Part 3 (1 .4) 

Dents — 

Part 2 (2.3.6), (2.4.4), (S1.4.2), (S6.5.5), 
(S6.13), (S6.14), (S6.15), (S7.8.2), 

Deposits, Waterside 

Parti (2.8.1); Part 2 (2.2.9); Part 3 (SI .2.13.1 ) 

Derating — 

Part 2 (4.4.4), (S5.2); Part 3 (3.4.1) 

Design — 

Part 1 , Part 2, and Part 3 (Foreword), 
(Introduction); Part 2 (2.2.10.4), 
(2.2.12.3), (2.2.12.4), (2.3.5), (2.3.6), 
(2.4.2),( 2.4.3), (3.3.3), (3.3.3.3), 
(3.3.3.5), (4.5.4), (S2.10), (S2.1 1), 
(S5.2.1), (S5.2.3), (S5.3.2), (S6.7), (S6.16); 
Part3 (1.2), (1.5.1), (1 .6.5.1), (1 .8.5.1), 
(3.2.4), (3.2.5), (3.3.5.2), (3.4), (3.4.4.1), 
(S4.17.2), (S6.7.1), (Supplement 8) 

Device Data — 
Part 2 (2.5.1 ),(2.5.2) 

Device Requirements — 
Parti (4.5.1), (5.3.1) 

Distribution of "TR" Forms — 

Part 3 (5.3), (5.4), (S3.2), (S4.14.4), (S6.18.1) 



Documentation — 

Part 1 (S1 .3), (Section 9); Part 2 (1 .5.4 c)), 
(4.4.2), (4.4.3), (4.5.5), (Section 5), 
(S2.6.2 e)), (S2.7.2), (S2.11), (S5.2.3), 
(S6.3), (S6.12.3), (Section 9); 
Part 3 (5.2), (S2.12), (S4.14.2), (S4.14.3), 
(S4.14.4),(S6.17.3), (S7.10.3), (Section 9) 

DOT (Transport Tanks) — 

Part 2 (Supplement 6); Part 3 (Supplement 6) 

Drains — 

Part 1 (2.4.3), (2.6.3), (3.6.3); Part 2 (2.2.6), 
(2.2.12.2), (2.2.12.3) 

Drawings — 

Part 2 (2.2.12.9), (2.3.5), (4.4.5), (S4.5), 
(S6.5.3), (S6.16) (8.4); Part 3 (1.7.7.5), 
(3.2.3), (S4. 16.2) 



Economizers — 

Parti (2.9.4); Part 2 (2.2.12.1) 

Eddy Current — 

Part 2 (2.3.6.4),(4.2.6), (S7.3.1) 

Electrical — 

Part 2 (2.2.12.4), (2.2.12.6), (S5.3.2.5), 
(S6.6.3.1) 

Electrical (Installation) — 
Parti (2.5.3), (3.5.3) 

Emergency Valves and Controls — 

Part 1 (2.5.6), (3.5.6); Part 2 (S6.4.7.4.4.2) 

Engineering Design — 
Part 2 (3.3.3),(3.3.3.5) 

Equipment Certification — 

Part 1 (1 .4.2) 

Equipment Operation — 

Part 2 (1.4.2) 



289 



NATIONAL BOARD INSPECTION CODE 



Erosion — 

Part2 (1.5.1), (2.2.8), (2.2.10.4), (2.2.12.2), 
(2.2.12.4 b)), (2.2.12.5), (2.2.12.7 b)), 
(2.3.3), (2.3.6), (2.4.4), (2.4.5), (3.3.1), 
(4.4.6), (4.4.7), (S1 .4.2.9), (S1 .4.2.13), 
(S1 .4.2.1 5), (SI .4.2.1 6), (SI .4.2.1 7), 
(S1 .4.2.1 8), (S1 .4.2.20), (S1 .4.2.32), 
(S1 .4.2.32), (S1 .4.2.33), (S3.4.1), (S5.3.1), 
(S6.3.1), (S6.13.2) 

Estimating Remaining Service Life and 

Inspection Intervals — 
Part 2 (4.4.7.1), (4.4.4), (4.4.5) 

Evidence of leakage, 
Boilers — 

Part 2 (2.2.5), (2.2.7), (2.2.10.2), (3.4.8), 
(3.4.9), (S2.5.2.2)(4.3.3); Part 3 (S2.11.3), 
Piping — 

Part 2 (2.4.4),(2.4.6), 
Pressure Vessels — 
Part 2 (2.3.3), (S4.6.2), (S6.13.2), 
(S6.1 3.9), (S6. 14.6.3), (S7.4) 

Examination — 

Part 1 (SI .6), (5.4); Part 2 , (2.3.5.4), (2.3.6), 
(2.4.5), (Section 4), (S1.4.2), (S2.4), 
(S2.4.4), (S2.5), (S3.4), (S4.5), (S5.5), 
(S6.13.), (S6.16), (S7.3), (Section 9); 
Part 3 (Section 4), (4.4), (S4.13.1), (S5.2), 
(S6.10), (S6.12), (S6.17) 

Examples of Repairs and Alterations — 
Part 3 (3.3.3), (3.4.3) 

Exfoliation — 

Part 2 (2.4.4), (3.3.1(g)), (S6.6.3.1(e)) 

Exhibits — 

Part 3 (1 .6.5.1 (q)), (1 .7.7.5(p)), (1 .8.5.1 (s)) 

Exit and Egress — 
Parti (2.4.1), (3.4.1) 

Expansion Tanks — 

Parti (3.7.9.1), (3.7.9.2); Part 2 (2.2.12.3), 
(2.3.6.3) 



Expansion and Support — 
Parti (2.7.3), (3.3.1 .1), (3.7.9), (4.3.1 ),(4.3.3), 
(5.2.6); Part 2 (2.4.7) 

External Inspections, 
Boilers — 

Part 2 (2.2.5) 

External Weld Metal Buildup — 

Part 3 (3.3.4.3(e)) 

FRP — 

Part 2 (S4.7), (S4.9.1), (S4.9.2) 

Graphite — 

Part 2 

PRD — 

Part 2 (2.5.8) 

Piping — 

Part 2 (2.4.1) 

Pressure Vessels — 

Part 2 (2.3.3), (S6.1 3.6), (S6.14.3), 

(S6.14.5),(S7.4) 



Failure Mechanisms — 
Part 2 (Section 3), (4.4.4), (4.4.8), (S2.4), 
(S6.6) 

Fatigue — 

Parti (S1.3 a), (SI .4.6); Part 2 (3.3.2), (3.4.1), 
(4.4.6), (4.4.8.6), (S5.2.1), (S6.6.4) 

Federal Railroad Administration (FRA) — 
Part 2 (S1 .3),(S1 .4.2.9), (S1 .4.2.1 0), 

(S1 .4.2.1 3), (S1.4.2.17), (S2.1); Part 3 

(S1.1.1) 

Feedwater — 

Parti (2.5.1), (3.7.4), (3.8.1); Part 2 (2.2.8), 
(2.2.11), (2.2.12.5 b)), (S2. 7.1), (S2.9), 
(S2.14) 

Fiber-Reinforced Thermosetting Plastic 
Pressure Equipment (RTP, FRP) — 

Part 2 (Supplement 4); Part 3 (Supplement 4) 

Field Repairs for Relief Devices — 
Part 3 (S7.7) 



29D 



NATIONAL BDARD INSPECTION CODE • PART 2 — INSPECTION 



Firebox — 

Part 2 (2.2.10.2), (2.2.12.9), (S1.1), (S1.4.2), 
(S1.5), (S2.4), (S2.11), (S2.13);Part3 
(S1.2.11.1), (S1.2.11.2),(S2. 13.10.4), 
(S2.13.11) 

Fire Damage — 

Part 2 (4.4.8.5),(5.3.8.5), (S6.5.5.1), 
(S6.15.3.5),(S7.4) 

Fittings — 

Parti (2.6.3), (2.7.3), (2.7.5), (2.9.1 .1), (3.8); 
Part 2 (2.3.6.2), (S2.9), (Section 9); 
Part 3 (SI .2.13) 

Flanges — 

Part 1 (5.2.3); Part 2 (2.2.10.3); Part 3 
(3.3.4.3(c)) 



Galvanic Corrosion — 
Part 2 (3.3.1) 

Glossary — 

Part 1 , Part 2, and Part 3 (Section 9) 

Graphite Pressure Equipment — 
Part 2 and Part 3 (Supplement 3) 

Grooving — 

Part 2 (2.28),(3.3.1), (S1.4.2), (S6.6.3.1); 

Part 3 (S2. 13.9.1), (S2.13. 10.1), 

(S2.13.11 .1) 

Gage Glass — 

Part 1 (2.8.1 h)), (3.8.1.2); Part 2 (2.10.5), 

(2.10.7)(S2.7.1), (S2.8.2), (S2.1 1 .4 f) 5)), 

(S2.13.5) 



Forced Flow Steam Generators — 
Part 1 (2.9.1 .3), (Section 9); Parts 2 & 3 
(Section 9) 

Forms — 

Parti (3.10.3); Part 2 (1.5.4), (S1 .3), 

(S2.7.3.1) (S2.11), (S2.7.3.1),(Section5); 

Part 3 (Section 5) 

Foundations — 

Parti (2.3.1) 

Fractures — 

Part 2 (See Brittle Fractures) 

Fuel — 

Part 1 (2.5.2), (3.5.2), (3.8.1 .5), (3.8.2.4) 

Fusible Plugs — 

Part 2 (S1 .4.2.25), (S2.4.3), (S2.8.4), 

(S6.4.7.5.3), (S6.15.1 m)), (S6.1 5.3.3); 

Part 3 (S2. 13.14.3) 



H 



Hangers — 

Parti (3.3.1 .1),(5.2.6) 

Heat Treatment — 

Part 3 (2.5), (S2.10), (S6.9), (S7.13), 

High Temperature Water Boiler — 
Parti (3.9.5.3), (2.2 b)), (2.5. 1.2 g)), 

(2.6.3.1 g)), (2.8.3), (2.9.1), (2.9.1.3), 

(2.9.1.5.1) 

Historical Boilers — 

Part 2 and Part 3 (Supplement 2) 

Inspection — 

Part 2 (S2.7), (S2.11) 

Storage — 

Part 2 (S2.13) 

Repair — 

Part 3 (Supplement 2) 

Safety Procedures — 

Part 2 (S2.14) 



Gages — 

Parti (2.8), (3.8.1.1), (3.8.2.1); Part 2 

(2.2.10.5), (2.3.5.1), (2.4.8.1), (S1. 4.2.27), 
(S2.6.1), (S2.8.5); Part 3 (4.3), (SI .2.1 3 



Hydrogen Attack ■ 
Part 2 (3.4.5) 



29 1 



NATIONAL BOARD INSPECTION CODE 



Hydrogen Damage — 
Part 2 (3.4.6), (4.4.6) 

Hydrogen Embrittlement ■ 
Part 2 (3.4.4), (S6.6.4) 



i 



Illegible NamepSates — 

Part 2 (5.2.1), (S6.5.2); Part 3 (5.9.5) 

Enquiries — 

Part 1, Part 2, and Part 3 (Section 8) 

Inservice Inspection — 
Part 2 (1.5), (2.5.4), (S1.4.2), (S2.7), (S3.4), 
(S4.2), (S5.1), (S7.3) 

Inspection and Test Frequencies (Pressure 

Relief Devices) — 
Part 2 (2.5.8) 

Inspection and Test Methods — 
Part 2 (Section 4) (S2 .4.4.2), (S2.5); Part 3 
(4.4.1), (4.4.2) 

Inspector Qualifications (FRP) — 
Part 3 (S4.2) 

Inspector Duties (DOT) — 
Part 2 (S6.4.6), Part 3 (S6.7.1) 

Installation Condition — 

Part 2 (2.3.2),(2.5.8) 

Installation Requirements — 

Part 1 (All sections) 

Insulated Vessels, Inspection — 
Part 2 (2.3.6.4(b)), (S4.7.1) 

Instruments and Controls — 
Part 1 (2.8), (2.9.2), (3.5.6), (3.8), (4.4); Part 2 
(2.2.12.12g)) 

Interface with Owners Repair/Replacement 

Program (Nuclear) — 
Part 3 (1.8.6) 



Intergranular Corrosion — 

Part 2 (3.3.2), (3.44) 

Internal Inspections — 

Part 2 (1.5.3), (2.3.4), (2.4.5), (S4.8), (S4.9.2, 
(S6.12.2), S6.13.4), (S6.14.3),(S7.5) 

Interpretations — 

Part 1, Part 2 and Part 3 (Introduction), (8.4), 
(Section 10) 

Interrupted Service — 

Part 2 (4.4.7.2 g)) 

Insulation Material/Insulation — 
Part 1 (3.3.2); Part 2 (2.2.7), (2.3.3), (2.4.6), 
(S2.11), (S7.4) 

Inspector — 

Parti (2.10), (4.6), (S1. 2); Part 2 (1.4), (1.5), 
(2.2), (2.3), (2.4), (2.5), (Section 4), 
(S4.5), (S6.4.2); Part 3 (1.3), (3.3.2), 
(3.3.4.1), (3.3.5), (3.4.1 ),(3.4.4), (4.4.1), 
(4.4.2), (S2.8), (S2.9), (S2.10), (S3.2), 
(S4.2), (S6.7.1) 



I 

Jurisdiction — 

Part 1 (Foreword), (Introduction), (1 .4.3); 
Part 2 (Foreword), (Introduction), (1.2), 
(2.5.8), (5.3.1), 0,(4.5. 7),(),(S1. 2), 
(S2.3), (S6.3), (S7.2); Part 3 (Foreword), 
(Introduction), (3.3.2), (3.3.4.3e)), (3.4.1 
e)), (3.4.2 g)), (4.2 a)), (4.4 d)), (4.4.1 
a)2)), (5.9.5 a)), (S2.2 b)), (S4.16.4), 

Jurisdictional Authority — 

Part 1 (Foreword); Part 2 (Foreword), (S7.1); 
Part 3 (Foreword), (S7.10) 

Jurisdictional Participation — 

Part 3 (1.7.2) 

Jurisdictional Precedence — 

Part 1, Part 2, and Part 3 (Introduction) 



292 



NATIONAL BOARD INSPECTION CODE • PART 2 — INSPECTION 



Jurisdictional Requirements — 

Parti (1.4), (2.3.1), (4.3.1); Part 2 (1.5), 
(2.2.4), (2.2.11), (2.5.3),(2.5.8), (4.2), 
(4.4.3), (4.5.7),(S2.4.1), (S4.9.1), (S4.9.2) 



K 

Knuckles — 

Part 2 (2.2.8 e)), (2.3.3 e)), (4.4.7.2), (4.4.8.7); 
Part 3 (S1.2.11.5), (S2. 13.11) 



Ladders and Runways — 
Part 1 (2.4.2), (3.4.2); Part 2 (2.3.4 b) 3)), 
(4.4.8.5) 

Lamination — 

Part 2 (3.4.7), (4.2.3), (4.4.8.3), (S2.5.4), 
(S3.4), (S4.4), (S4.8.1) 

Lap Joints/Seams — 

Part 2 (3.3.1 d)), (3.4.9 d)), (S1 .4.2.1), 

(S2.10.6), (S2.10.7), (S2.11),(S6.6.3.1) h)); 
Part3 (SI .2.12), (S1 .2.12.1), (S2.13.13) 

Leakage — 

Part 2 (2.2.5), (2.2.7), (2.3.3), (2.4.6), (S4.6.2), 
(S6.4.7.4), (S6.13.9), (S7.4), (S7.6) 

Leak Testing — 

Part 2 (4.3.2), (S6.13.9), (S6.1 4.6.2); Part 3 
(4.4.1 c)) 

Level Indicating Devices — 

Parti (4.4.1) 

Lift Assist Testing — 

Part 1 (Section 9); Part 2 (2.5.7), (Section 9); 
Part 3 (4.5.3), (Section 9) 

Limitations (Historical Boilers) — 

Part 2 (S2.10.7) 



Lighting — 

Part 1 (2.5.5), (3.5.5); Part 2 (2.2.4), (S1.4.27), 
(S4.6.3), (S6.16) 

Line Corrosion — 

Part 2 (3.3.1(f)) 

Liquid Ammonia Vessels — 

Part 2 (2.3.6.4) 

Liquid Penetrant Examination — 

Part 2 (4.2.3), (4.4.8.5), (S2.5.1),(S2.5.4), 
(S4.6.3), (S6.16); Part 3 (3.3.4.1), 
(3.3.4.2), (3.3.4.2), (3.3.4.3), (S2.13), 
(S4.3) 

Liquefied Petroleum Gas Pressure Vessels — 
Part 2 (Supplement 7) 

Liquid Pressure Testing — 

Part 2 (S2.4.4.2), (S2.6.1), (S2.7.3.1), (S2.11), 
(S5.6); Part 3 (4.4.1 a)), (4.4.2 a)), 
(S6.17.1 a)) 

Loadings — 

Parti (2.3.1), (3.3.1.1 a)), (4.3.1), (5.2.6); 
Part 2 (S6.16); Part 3 (3.4.2), 

Local PWHT — 

Part 3 (2.5.2) 

Local Thinning — 

Part 2 (4.4.8.7), (S5.3.1); Part 3 (S5.6.1) 

Locomotive Boilers — 

Part 2 (2.2.12.4), (Supplement 1); Part 3 
(Supplement 1) 
Inspection — 
Part 2 (S1 .4) 
Storage — 
Part 2 (S1 .5) 

Low-Water Fuel Cutoff — 
Part 1 (2.8.1), (3.8.1.5), (3.8.2.4); Part 2 
(2.2.1 0.5),(2.2.1 0.7) 



Z93 



NATIONAL BOARD INSPECTION CODE 



M. 



Macroscopic Corrosion Environments — 
Part 2 (3.3.1) 

Crevice Corrosion — 

Part 2 (3.3.1 (d)) 

Erosion Corrosion — 

Part 2 (3.3.1 (c)) 

Exfoliation — 

Part 2 (3.3.1 (g)) 

Galvanic Corrosion — 

Part 2 (3.3.1 (b)) 

Grooving — 

Part 2 (3.3.1 (i)) 

Line Corrosion — 

Part 2 (3.3.1 (f)) 

Pitting Corrosion — 

Part 2 (3.3.1 (e)) 

Selective Leaching — 

Part 2 (3.3.1 (h)) 

Uniform Corrosion (General) — 

Part 2 (3.3.1 (a)) 

Magnetic Particle Examination — 
Part KS1.6); Part 2 (4.2.2), (4.4.8.5), (S2.5), 
(S2.5.5), (S6.1 3.6.3), (S7.3.1); Part 3 
(3.3.4.1), (3.3.4.2), (3.3.4.2), (3.3.4.3), 
(S2.13), (S5.6.2) 

Materials — 

Part 2 (2.1), (2.2.1 2.3),(2.3.6.4); Part 3 

(1.6.5.1 i))(3.2.1), (S1.1.3), (S2.7), (S4.8), 

(S6.4), (S7.4) 

QC Program — 

Part 3 (1 .6.5.), (1 .7.7.7.5 h)), (1 .8.5.1 h)) 

Selection — 

Part 2 (3.3.3.3) 

Metallographic — 

Part 2 (4.2.7), (4.4.8.1), (S5.5), (S7.3.1) 

Methods, 

Inspection and Test — 
Part 2 (Section 4) 
Locomotive Inspection — 
Part 2 (SI .4.1) 
Repair — 
Part 3 (3.3.4) 
Repair/Alteration, 
Examination/Testing — 
Part 3 (4.4.1), (4.4.2) 



Metric Policy (NBIC Policy for 

Metrication) — 

Part 1 , Part 2, and Part 3 (Section 7) 

Microscopic Corrosion Environments — 
Part 2 (3.3.2) 

Corrosion Fatigue — 

Part 2 (3.3.2(c)) 

Intergranular Corrosion — 

Part 2 (3.3.2(a)) 

Stress Corrosion Cracking (SCC) — 

Part 2 (3.3.2(b)) 

Minimum Thickness — 
Part 2 (4.4.7.2), (4.4.8.4),(S2.6.2), (S2.10.3), 
(S6.6.3.1), (S6.13); Part 3 (3.3.4.3), (3.4.2) 

Modifications (DOT) — 
Part 2 (S6.2), (S6.4), (S6.6.2), (S6.7); Part 3 
(S6.16.3) 

Mudring — 

Part 2 (S1.4), (S1 .5), (S2.13.1); Part 3 
(SI .2.11 .4) 



M. 



Nameplates — 

Part 2 (2.5.2), (5.2), (S6.5.2); Part 3 (5.9.1), 
(5.11), (5.12),(S6.14.1), (S6.19.2) 

National Board "R", "VR" and "NR" 
Symbol Stamp — 

Part 3 (1.5.1),(1.6.4), (1 .7.6), (1 .8.4), 

Nondestructive Examination — 

Parti (2.10.3), (S1.6); Part 2 (4.2), (S2.4.4.1), 
(S5.5), (S7.3.1); Part 3 (4.2), (4.4.1), 
(4.4.2), (S2.11), (S4.12), (S6.10), (S6.17.1) 

"NR" Accreditation — 
Part 3 (1.8) 

"NR" Symbol Stamp — 
Part 3 (1 .8.4), 

Nuclear Valves (Repair) — 
Part 3 (1 .7.4) 



294 



NATIONAL BOARD INSPECTION CODE • PART Z — INSPECTION 



y/ NV"-Stamped Pressure Relief Devices 
Part 3 (1 .7.4), (Supplement 9) 



O 



Oil Heaters — 

Parti (3.7.1) 

Operating Parameters (Yankee Dryers) — 
Part 2 (S5.2.1) 

Operating Systems — 

Parti (2.7), (3.7); Part2(S3.3) 

Organization of the NBIC — 

Part 1 , Part 2, and Part 3 (Introduction) 

Overheating — 

Part 2 (2.12),(3.4.8),(S1 .4.2.8 g), 

(S1.4.2.17 f», (S1 .4.2.18f)), (S4.7.2) 

OwnerUser — 

Part 1 (1 .1 ), (1 .2 b)); Part 2 (S1 .3), (S2.4), 
(S2. 7.3.1), (S6.4.6), (S6.14.3); Part 3 
(1.3 b)), (4.5.2), (SI. 1.1), (S5.5), (S7.9), 
(S7.10), (S7.11) 

OwnerUser Inspection Organization — 
Part 3 (1.6.1 c)2)), (3.3.5.2 b)), (3.4.4.1) 



Performance Testing — 
Part 3 (4.5) 

Permissible Mounting (SV) — 

Part 1 (3.9.1.1), (3.9.4.2), (4.5.6), (5.3.6) 

Personnel Safety — 

Part 1 (Introduction), (4.5.6 f)), (5.3.6 f)), 
(S1 .5 b)); Part 2 (Introduction), (1 .4), 
(S2.4.), (S6.11), Part 3 (introduction) 

Piecing Tubes/Pipe — 
Part 3 (3.3.4.5), (S2.13.7) 

Pilot Operated Safety Relief Valves — 
Part 2 (2.5.1); Part 3 (S7.14.3) 

Piping — 

Part 1 (3.7.6), (3.9.1.5), (4.3.3), (Section 
5); Part 2 (1.5), (2.4), (2.5.5.2), 
(S1.4.2),(S2.9), (S6.13.2); Part 3 (S8.3) 

Pitting Corrosion — 

Part 2 (3.3.1), (S1.4.2), (S6.6.3.1) 

Plug Stitching — 

Part 3 (S3.5.3),(S3.5.3.1), (S3. 5. 3.2) 

Pneumatic Testing — 

Part 2 (S6.1 3.6.1); Part 3 (4.4.1(b)), (4.4.2(b)) 

Portable Tank (DOT) — 

Part 2 (S6.14) 



Parts — 

Parti (2.6.3.3),, (S1.3); Part 2 (2.2.10), 

(2.3.5); Part 3 (1.7.7.5 h)), (3.2.2), (3.3.3), 
(4.5.4), (5.2.2), (5.9.6.5), (S2.7.2), (S3.5.1 
c)), (S4.9), (S5.3.1), (S7.3) 

Patch Bolts — 
Part 3 (S1.2.8) 

Patches — 

Part 3 (3.3.4.6), (S1.2.11.2), (S2.13.12.3) 

Performance Qualification — 

Part 3 (2.2.3), (S4.10.2), (S6.8.3), (S7.12.3) 



Post-Inspection Activities — 
Part 2 (1.5.4), (S2.4.2), (S6.1 2.3) 

Postweld Heat Treatment — 

Part 3 (2.5.2), (S2.1 0), (S6.9.2), (S7.1 3.2) 

Potable Water Heaters — 
Parti (3.2.3), (3.7.5.2), (3.7.7.2) 

Preheating — 

Part 3 (2.5.1), (S2.10), (S6.9.1), (S7.13.1) 

Pre-Inspection Activities — 

Part 2 (1.5.2), (2.2.3), (S2.4.1), (S6.12.1) 



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NATIONAL BOARD INSPECTION CODE 



Preparation of Forms — 
Parti (1.4.5); Part 2 (5. .3.1); Part 3 (5.2.1), 
(5.2.2) 

Preservation — 

Part 2 (SI .5.4), (S2. 13.2), 

Pressure Control — 
Parti (3.8.1.4) 

Pressure Gages — 

Part 1 (2.8.2), (4.4.2); Part 2 (2.2.10.5), 
(2.3.5.1), (2.4.8.1), (S2.8.5); Part 3 (4.3) 

Pressure Relief Devices — 

Part 1 (2.9), (3.9), (4.5); Part 2 (2.2.10.6), 

(2.5); Part 3 (4.5), (5.9), (Supplement 7) 

Mounting — 

Part 1 (2.9.5.1), (3.9.1.1), (4.5.3), (5.3) 

Pressure Relief Valve Nameplates — 
Part 3 (5.9.1), (5.9.6), (Supplement 7), 
(Supplement 8) 

PressureReducing Valves — 

Part 1 (Supplement 2) 

Pressure Testing — 
Part 2 (4.3.1) 

Alterations — 

Part 3 (4.4.2) 

FRP Vessels — 

Part 3 (S4.15), (S4.17.6) 

Inservice — 

Part 2 (4.3.1) 

Installation — 

Parti (2.10.2) 

Parts — 

Part 3 (4.5.4) 

Repairs — 

Part 3 (4.4.1) 

Yankee Dryers — 

Parti (S1.5); Part 2 (S5.6) 

Pressure Vessels, 

Fiber-Reinforced Thermosetting 

Plastic (FRP) — 

Part 2 and Part 3 (Supplement 4) 

Graphite — 

Part 2 and Part 3 (Supplement 3) 



Inspection — 

Part 2 (2.3) 
Installation — 

Part 1 (Section 4) 

LP Gas (Propane) — 

Part 2 (Supplement 7) 

Relief — 

Part 2 (2.3.5.2) 

Section VIII Div 2 or 3 — 

Part 3 (3.3.5), (3.4.4) 

Yankee Dryers — 

Part 1 (Supplement 1), Part 2 and Part 3 

(Supplement 5) 

Process Variables (Corrosion) Provisions for 

Expansion/Support — 
Part 2 (2.4.7); Part 3 (SI .2.3 j)), (SI .2.5 c)), 

(Sl.2.10 d) 

Pumps — 

Parti (2.5.1.3) 



Q. 



Quality Systems — 

Part 3 (1.6.5), (1.7.7), (1.8.5), (S7.10.4) 

Qualifications, 

FRP Performance — 

Part 3 (S4.10.2) 
Inspector — 

Part 2 (S4.5), (S6.4); Part 3 (S4.2) 

NDE — 

Part 3 (4.2) 

PRV Personnel — 

Part 3 (S7.11) 

Welders Performance — 

Part 3 (S7.12.3), (2.2.3), (S6.8.3) 

Quick-Actuating Closures — 
Part 2 (2.3.6.5) 

Quick-Disconnect Couplings — 
Part 2 (2.4.8.3) 



296 



NATIONAL BOARD INSPECTION CODE • PART 2 — INSPECTION 



u 



"R" Symbol Stamp — 
Part 3 (1 .6) 

Radiography — 

Part 2 (4.2.5); Part 3 ((4.2), S2.11), (S6.10) 

Records Review — 

Part 2 (2.2.11), (2.3.5.4); Part 3 (S2.12), 
(S4.10.3), (5.2) 

Reference to Other Codes arid Standards — 
Part 1 (Introduction); Part 2 (Introduction), 
(1.3), (2.2.12.2), (S1. 3); Part 3 
(Introduction), (1.2), (2.4), (SI .2.12.1 b)) 

Re-ending — 

Parts 1 and 2(Section 9); Part 3 (3.3.4.5), 
(S1.2.9.1), (S2.13.7) 

Registration of "R" Forms — 

Part 3 (5.5), (S6.18.2) 

Remaining Service Life Assessment — 
Part 2 (4.4.4) 

Removal of Stamping — 
Part 3 (5.8), (S6.14.1) 

Renewal of "VR" Certificate — 
Part 3 (1.7.5) 

Repair — 

Part 3 (3.3), (3.3.3), (3.3.4), (3.3.5), (SI .2.1), 
(S1.2.10), (S1.2.11), (S2.4), (S2.13), 
(S2.13.14), (S3.2), (S3. 5), (S4.5), (S4.18), 
(S5.4), (S5.6), (S6.16), (S7.2) 

Replacement Parts — 

Part 3 (3.2.2), (S2.7.2), (S4.9), (S5.3.1), (S6.5), 
(S7.5) 

Replacement Stamping — 

Part 2 (5.2), ((5.2.2); Part 3 (5.8), (5.9.3), 
(5.9.5), (5.9.6), (5.10), (5.11) 

Re-rating — 

Part 1 and Part 2 (Section 9); Part 3 (3.4.1), 
(S4.17.5), (Section 9) 



Responsibility — 

Part I (1.4.1); Part 2 (S2.3); Part 3 (S2.3) 

Return Pipe Connections — 
Parti (3.7.6) 

Return to Service — 
Part 2 (S1.5.6) 

Risk-Based Inspection — 
Part 2 (4.5) 

Rivets/Riveted Joints — 
Part 2 (2.3.3 e) 7)), (S1.4.2), (S2.10.2); Part 3 
(3.3.4.4(b)), (S2.13.13) 

Rupture Discs — 

Part 2 (2.5.5.3), (S6.1 5.3.3) 

Routine Repairs — 

Part 3 (3.3.2), (S3.3), (S4.16.4) 



Safety — 

Part 2 (1.4),), (2.2.6), (2.3.5.2), (S2.14), 
(S6.11) 

Safety Devices — 

Part 1 (2.9); Part 2 (2.3.5.2), (2.4.8.2), (2.5), 
(S2.8) 

Safety Valve Capacity — 

Parti (2.9.1.3), (S2.2); Part 2 (2.5) 

Safety/Safety Relief Valves — 
Part 1 (2.9), (3.9.2), (3.9.3), (3.9.4), 
(3.9.5), (Supplement 2); Part 2 (2.5), 
(S2.8.1XS2.11 f)); Part 3 (Supplement 7) 

Scale and Sludge — 

Part2 (2.2.9), (2.2.12.5), (2.2.12.7), 

(2.2.12.8), (2.2.1 2.9), (S1 .4.2), (S2.1 1 ) 

Scope of Activities (Accreditation) — 
Part 3 (1.5.2), (1.6),(1.7), (1.8.1) 



297 



NATIONAL BOARD INSPECTION CDDE 



Seal Welding — 

Part 3 (3.3.4.4), (SI .2.4), (S2. 13.3) 

Seams and Joints — 

Part3 (S1.2.12), (S2.13.13), (S2.13.13.5) 

Service Conditions — 

Part 2 (2.2.2), (2.3.2), (2.4.2) 

Settings — 

Parti (2.3.1), (3.3.2) 

Set Pressure — 

Part 1 (2.9.1.4), (4.5.5), (5.3.5); Part 2 (2.5) 

Shipping and Transporting — 

Part 2 (2.5.6) 

Siphons (Thermic) — 

Part 2 (S1 .4.2.1 8),(S1 .5.4); Part 3 (SI .2.9.4) 

Spring Loaded Pressure Relief Valves — 
Part 3 (S7.14.2) 

Stamping — 

Part 2 (Section 5); Part 3 (5.7), (5.8), (5.9), 
(5.10), (5.11), (5.12), (S5.5), (S6.1 4), 
(S6.17.2) 

Standard Welding Procedures — 
Part 3 (2.2.2), (2.3), (S6.8.2), (S7.12.2) 

Stays/Staybolts — 

Part 2 (2.2.10.2), (S1 .4.2.9),(S1 .4.2.10), 
(S2.1 0.4.1); Part 3 (3.3.4.7), (SI .2.1), 
(S1.2.3),(S2.13.1), (S2.13.2), (S2.13.3), 
(S2.13.4) 

Stayed Surfaces — 

Part 2 (S1.4.2.8), (S2.10.4); Part 3 (S2.13.10), 
(S1.2.11) 

Steam Heating Boilers — 

Part 1 (Section 3); Part 2 (2.5.7d)), (2.5.8c)) 

Steam Supply — 
Parti (2.7.3) 

Stop Valves — 

Parti (2.5.1.4), (2.7.3), (3.7.5) 



Storage Methods — 
Part 2 (SI .5.1), (S2.13.1) 

Structural Attachments — 
Parti (2.3.1) (3.3.1), (5.2.6); Part 2 (S4.7.3), 
(2.3.3 c)), (2.3.6.3 b)3)) 

Structural Steel — 

Part 1 (2.3.2), (3.3.3) 

Supplements — 

Part 1 , Part 2, and Part 3 (Introduction), 
(Section 6) 

Supports — 

Parti (2.3.1), (3.3.1), (4.3.1), (5.2.6); Part 2 
(2.2.10.4), (2.3.6.1 b)5)), (2.3.6.2 b) 3)), 
(2.3.6.3 b)3)), (2.4.7), (S1. 4.2.28) 

Superheaters — 

Parti (2.9.3); Part 2 (2.2.12.1 c)j, (SI .4.2.1 6), 

(S1.5.4d)) 

Surfaces (FRP) — 

Part 2 (S4.7.2) 

Systems Testing — 
Parti (2.10.4) 



Technical Inquiries — 

Part 1, Part 2, and Part 3 (Section 8) 

Temperature Controls — 

Parti (2.8.3), (3.8.2.3) 

Temperature Effects — 

Part 2 (3.4.3), (2.5.7), (3.4.1), (3.4.2), (3.4.6), 
(3.4.7) 

Test Systems (PRV) — 
Part 3 (Supplement 8) 

Testing — 

Part 1 (2.10), (3.10), (4.6); Part 2 (2.5.7), 
(4.3), (S2.6); Part 3 (Section 4), (S6.1 7), 
(Supplement 8) 



Z9B 



NATIONAL BOARD INSPECTION CODE • PART 2 — INSPECTION 



Thermometer — 

Parti (3.8.2.2), (3.8.3.2) 

Thermal Expansion — 

Part 1 (3.7.9); Part 2 (2.2.12.8), (2.4.4), (2.4.7) 

Temperature and Pressure Relief Valves — 
Parti (3.9.1.6) 

Thinning — 

Part 2 (S5.3.1) 

Ton Tanks (DOT) — 
Part 2 (S6.15) 

Training — 
Part 3 (S7.11) 

Transport Tanks (DOT) — 

Part 2 and Part 3 (Supplement 6) 

Tubes — 

Part2 (2.2.12.2), (2.2.12.9), (S2.11), (S2.13); 

Part 3 (3.3.3), (3.3.4.3(d)), (3.3.4.5), 

(S1.2.9), (S2.13), (S3.3) 

Tubesheet — 

Part 2 (S2.11); Part 3 (S1 .2.1 1 .6), (S2.13.12) 

Thermal Fluid Heaters — 
Part 2 (2.2.12.3) 

Threaded Connections/Openings — 

Parti (3.9.1.2); Part 2 (S2.9); Part 3 
(S1.2.12.2) 

Threaded Stays, Bolts, Studs — 
Part 3 (S1.2.2), (S1.2.7), (S2.13.1), (S2.13.2), 
(S2.13.5) 

Throttle and Throttle Valves — 
Part 2 (S1 .4.2.21), 

Try Cocks — 

Part 2 (S2.8.3), (S2.7.1), 

Transport Tanks (DOT) — 
Part 2 (Supplement 6) 



JLL 



Ultrasonic Examination — 
Part 2 (4.2.4), (S2.5.3), (S2.6.2) 

Uniform Corrosion — 
Part 2 (3.3.1), ((S1.4.2), (S2.11), (S5.3.3), 
(S6.6), (S7.8.5) 

Units of Measurement — 

Part 1 , Part 2, and Part 3 (Introduction) 

Unstayed Areas — 

Part 2 (ST .4.1); Part 3 (S2.13.9), (SI .2.10) 



V. 



"VR" Symbol — 

Part 1 and Part 2 (Introduction); Part 3 
(Introduction), (1 .7), (Supplement 9) 

Vacuum Test — 
Part 3 (4.4.1(d)) 

Vaporizers — 
Part 2 (2.2.12.3) 

Valves — 

Parti (2.5.1.4), (3.7.5), (3.7.7), (5.2.4); 

Part 2 (2.3.6.4), (2.4.5), (S1.4.2), (S2.9), 

(S2.11),(S6.4.7.4.4) 

Ventilation Air — 
Part 1 (2.5.4), (3.5.4) 

Verification Testing (PRDs) — 
Part 3 (1.7.5.5), (1.7.5.6) 

Vibration — 

Part 2 (2.2.12.4), (2.2.12.7), (2.3.6.2) 

Visual Examination — 

Part 2 (4.2.1), (S2.5.2), (S4.4), (S6.13.1), 
(S6.4.7.3), (S6.15.2);Part3 (3.3.2), 
(S4.12), (S6.7.1), (S7.14.2), (S7.14.3) 

Volume (Feedwater) — 
Parti (2.5.1.1) 



299 



NATIONAL BOARD INSPECTION CODE 



ysL 



Wasted Areas — 

Part 3 (3.3.2), (3.3.4.3), (S2.13), (S2. 13.9.1) 

Water Column — 

Parti (3.8.1.3); Part 2 (2.2.10.3), (2.2.10.4), 
(S1 .4.2.26), (S2.11.5) 

Water Gage Connection — 

Part 3 (S1 .2.1 3.1); Part 2 (S1 .4.2), (S2.13), 
(S2.14.3) 

Water Gage Glass — 

Parti (3.8.1.2); Part 2 (2.2.10.5), (S1 .4.2), 
(S2.11) 



Wrapper Sheet 

Part 2 (S2.11) 



Yankee Dryers — 

Part 1 (Supplement 1 ); Part 2 and Part 3 
(Supplement 5) 



Water Heaters — 

Part 1 (3.2.3), (3.7.5.2), (3.7.7.2), (3.8.3); 
Part 2 (2.5.8) 

Waterside Deposits — 

Part 2 (2.2.9), (S1.4.2), (S2.13.4), 

Welds, 

Inspection — 

Part 2 (S2.8); Part 3 (S2. 8) 

Repairs — 

Part 3 

Welding — 

Part 1 (5.2.8); Part 3 (2.2), (SI .1 .2), (S1 .2.5), 
(S2.9), (S6.8), (S7.3), (S7.12) 

Welding Procedures — 

Part 3 (2.2.1), (S6.8.1), (S7.12.1) 

Welders Continuity — 

Part 3 (2.2.6), (S6.8. 6), (S7.12.6) 

Welders Identification — 

Part 3 (2.2.5), (S7.1 2. 5), (S6.8.5) 

Welding Methods — 

Part 3 (2.5.3.1), (2.5.3.2), (2.5.3.3), (2.5.3.4), 
(2.5.3.5) 

Welding Records — 

Part 3 (2.2.4), (S6.8.4), (S7.12.4) 



3DD 



Part 2